METHOD FOR OPTIMIZING A LIQUID CHROMATOGRAPHY SYSTEM AND SYSTEM FOR LIQUID CHROMATOGRAPHY

Abstract

The present invention relates to a method carried out in a liquid chromatography system, the method comprising: in a first configuration (I), in which a first separation column is fluidically connected to a separation pump and a detector, directing a flow from the first separation column to the detector by means of the separation pump in the first configuration (I); and switching the liquid chromatography system from the first configuration (I) to a second configuration (II), in which the first separation column is fluidically connected to a second pump and the detector, and directing a flow from the first separation column to the detector by means of the second pump in the second configuration (II). The present invention also relates to a corresponding system, a use, a computer program, a computer-readable medium, and a data carrier signal.

Description

[0001] The invention lies in the field of liquid chromatography, and in particular in the field of high-performance liquid chromatography. The present invention relates to a method carried out in a liquid chromatography system and to a liquid chromatography system. STATE OF THE ART

[0002] In general terms, liquid chromatography is an analytical technique in which a liquid sample is separated into its components, which are then detected. For example, the respective proportions can be quantified. Liquid chromatography generally achieves a separation between these components. A liquid chromatography system typically includes at least one pump, a sample preparation device (e.g., an autosampler), at least one separation column, and a detector.

[0003] To perform liquid chromatography, a sample is mixed with one or more solvents and subjected to a flow through the separation column and toward the detector by the action of a pump. The pump used in a liquid chromatography system can introduce a gradient into the separation column. This means that the composition of the mobile phase, i.e., the solvent passing through the separation column, can be changed over time using the pump. The time it takes for the different components of a sample to pass through the separation column depends on various factors, including their adhesion to the column, the solvent, the solvent flow rate, and the pressure of the solvent. Generally, the stronger the interaction between a component and the separation column, the longer the passage takes. This variation allows for the determination and analysis of the components of the sample.

[0004] Since, for example, the requirement for higher throughput may be important, the complexity of liquid chromatography systems can also increase. A tandem chromatography system generally includes more than one column. Using more than one column in a tandem chromatography system can reduce the time to results and costs by parallelizing certain steps of the process. For example, more than one column can be used simultaneously, which can optimally double the throughput.

[0005] As an example, a tandem chromatography system can incorporate a multitude of columns, and each column within this multitude can be used in a sequential workflow, i.e., one after the other. This allows chromatograms to be obtained sequentially, thus increasing the system's throughput. However, the workflow described above may not guarantee that the analytical quality is fully maintained, but may focus solely on increasing the system's throughput.

[0006] EP 2 449 372 B1 describes a liquid chromatography apparatus that is controllable for carrying out a chromatography process defined by target parameters and a sequence of operating procedures. The apparatus includes a process execution unit configured to execute the process using the set parameters and sequence, a determination unit for identifying deviations between the actual and expected results of the chromatography procedure, and an adjustment unit for modifying the operating characteristics based on these deviations, thereby compensating for differences without altering the chromatography procedure itself. While this disclosure can provide satisfactory results in some cases, it has certain disadvantages and limitations.For example, while attempting to at least partially compensate for a difference between an expected target result and an actual result, the method used must remain unchanged. Additionally, a number of target parameters are required, and a database is used. Furthermore, environmental distortions (e.g., a significant change in ambient temperature or pressure) are corrected.

[0007] US 9,694,301 B2 relates to a device for separating a liquid sample, comprising a first separation unit for initial separation, a first fluid drive for moving the sample through this unit, and a downstream second separation unit for further separation. A second fluid drive directs the sample at least partially through the second unit. The system further includes a fluid valve with interfaces connected to both fluid drives, enabling it to switch between them and facilitate sample separation. While this disclosure may provide advantages in improving the accuracy and / or precision of a liquid chromatography device, it may be more difficult to achieve higher throughput with it.

[0008] EP 0 403 680 B1 describes a device for optimizing the liquid chromatographic separation of a sample. It has the means to perform separations with selectable optimization parameters, such as the composition of the mobile phase. Using measured chromatographic data and a mathematical model, the device derives and displays the retention behavior of the sample. The user can select a desired optimization parameter via an input, and the resulting chromatogram is calculated and displayed. This allows the user to determine the optimal parameter value for the best results. The process is iterated with refined data until the desired optimum is reached.

[0009] EP 0 577 033 A1 describes a method for adjusting analytical conditions in liquid chromatography. It detects the relationship between the elution variation of a specific component and changes in the analytical conditions. The retention time of the specific component is measured, and if it deviates from a reference range, the analytical condition is adjusted accordingly. This new condition is used for subsequent analyses. If the adjusted condition is outside the permissible range, an anomaly message is triggered. Preferred adjustments include the time required to switch the elution solution, the column temperature, or the flow rate of the liquid feed pump.

[0010] US 10,722,816 B2 relates to a method for adjusting the gradient delay volume (GDV) in a liquid chromatography system, particularly in high-performance liquid chromatography. In this method, a desired GDV is determined or specified. If this desired GDV differs from the actual GDV of the system, the desired GDV is adjusted within a volume range from 0 to maximum using a volume adjustment device. This document also discloses an automatic sampler designed to implement this method.

[0011] EP 1 342 202 A1 describes a method and apparatus for automating the qualification process for chromatographic systems. This process uses automation technology and regression analysis. A trained operator initially prepares the chromatography system to ensure that samples, solvent, and the separation column are ready for analysis. The qualification of the detector, solvent supply system, sample manager, gradient dosing system, column heater, and system retardation volume is then performed automatically without further operator intervention. Regression analysis is carried out to calculate performance statistics to demonstrate the system's accuracy, linearity, and precision, and to assess its suitability for chromatographic analysis.

[0012] US 9,442,098 B2 describes compositions and procedures designed for chromatographic analysis and system quality control. These compositions contain a reference material with a standardized mixture of two or more compounds, which serves for benchmarking and troubleshooting of the chromatography system, rather than simply providing a standard solution for a single analyte. The procedure involves generating a chromatogram from this reference material using the chromatography system. The resulting chromatogram is then compared to a benchmark for the reference material. If the difference between the chromatogram and the benchmark is within an acceptable tolerance range, the system is considered to be functioning properly, allowing the analysis of further samples.If the difference exceeds the tolerance range, the system is flagged for troubleshooting based on the observed chromatogram discrepancies.

[0013] The teaching of US 10,775,355 B2 aims at a clinical diagnostic system that includes a sample preparation station for the automated preparation of samples containing analytes of interest, a liquid chromatography separation station with multiple liquid chromatography channels, and a sample preparation / liquid chromatography interface for loading prepared samples into these channels. The system also features a controller that manages sample assignments to predefined preparation workflows, each with a specific sequence of steps and a required completion time based on the analytes involved. Additionally, the controller assigns each prepared sample to a liquid chromatography channel according to the analytes and schedules an input sequence for the liquid chromatography channels to ensure that analytes from different channels elute in a non-overlapping sequence.Finally, the controller establishes a sequence that generates a sample output order that matches the planned input sequence of the liquid chromatography channel and starts it.

[0014] US 2018 / 0229152 A1 discloses a parallel arrangement of chromatography column modules housed in a rigid enclosure with a shared inlet and outlet. Each column module has a bed filled with chromatography medium and includes integrated fluid lines. When the modules are installed in the rigid enclosure, these lines connect each bed to the shared inlet and outlet. The length and / or volume of the fluid line from the shared inlet to each bed, and from each bed to the shared outlet, is substantially identical for all modules in the parallel arrangement.

[0015] Existing technologies primarily aim to improve the performance of a liquid chromatography system within a limited scope. For example, existing technologies may relate to the precision or efficiency of the workflow, the number of results obtained, the conformity with a specific criterion, or the throughput (in liquid chromatography systems).

[0016] However, existing technologies can have certain shortcomings and disadvantages. In particular, the time required for detector use may be far from optimal, leading to suboptimal resource utilization. Furthermore, relevant signals may be missing from the chromatograms in some state-of-the-art solutions.

[0017] The present invention at least partially mitigates some of the shortcomings of existing technologies. In particular, the present invention is directed at least partially towards the optimization of a liquid chromatography system over a broad range, including high throughput and / or consistent and reproducible chromatographic results and analyses and / or utilization of limited data storage space. BRIEF SUMMARY OF THE INVENTION

[0018] In one aspect, the present invention relates to a method carried out in a liquid chromatography system. The method comprises, in a first configuration (I) in which a first separation column is fluidically connected to a separation pump and a detector, directing a flow from the first separation column to the detector by means of the separation pump in the first configuration (I). The method further comprises switching the liquid chromatography system from the first configuration (I) to a second configuration (II), wherein the first separation column is fluidically connected to a second pump and the detector. The method further comprises directing a flow from the first separation column to the detector by means of the second pump in the second configuration (II).

[0019] In one embodiment, in the first configuration (I), a second separation column can be fluidically connected to the second pump and a disposal system. The method can include directing a flow from the second separation column to the disposal system by means of the second pump in the first configuration (I).

[0020] In the second configuration (II), the second separation column can be fluidically connected to the separation pump and the disposal, and the process can further include directing a flow from the second separation column to the disposal by means of the separation pump in the second configuration (II).

[0021] The procedure may involve switching the liquid chromatography system from the second configuration (II) to a third configuration (III), wherein the first separation column may be fluidically connected to the second pump and a disposal system.

[0022] The process can further include directing a flow from the first separation column to disposal by means of the second pump in the third configuration (III).

[0023] In the third configuration (III), the second separation column can be fluidically connected to the separation pump and the detector. The method can further include directing a flow from the second separation column to the detector via the separation pump in the third configuration (III).

[0024] The liquid chromatography system can be switched to a first switching time (T II ) from the first configuration (I) to the second configuration (II).

[0025] The liquid chromatography system can be switched to a second switching time (T III ) from the second configuration (II) to the third configuration, with the second switching time (T III ) after the first switching time (T II ) may be located.

[0026] A time difference t Verz between the second switching time (T III ) and the first switching time (T II ) can be applied to a volume V5 of the second separation column, to a volume V verb of fluid connections connected to the second separation column and based on a flow rate F of the separation pump.

[0027] In other words, the time difference t Verz This can correspond to the time required for a mobile phase flowing through the second separation column to traverse a volume that is the sum of the volume of the second separation column and the fluid compounds connected to the second separation column. The time difference t Verz This can therefore correspond to the time the mobile phase flowing through the second separation column requires to travel from the second pump to the detector. It can be particularly advantageous to have such a time difference t. VerzWhen detecting the mobile phase flowing through the second separation column with a detector, it must be taken into account that the detector may only detect this mobile phase after a time difference t. Verz with regard to the second pump starting.

[0028] The time difference t Verz can satisfy the following equation: tVerz=(V5+Vverb) / F.

[0029] The time difference t Verz can be in the range between 0 minutes and 100 minutes, preferably between 1 minute and 20 minutes, more preferably between 1 minute and 10 minutes.

[0030] At the first switching time (T II ) the flow rate F' of the second pump can be essentially equal to the flow rate F of the separation pump.

[0031] A flow rate F' of the second pump in the third configuration (III) can be considerably larger than the flow rate F of the separation pump in the third configuration (III).

[0032] The method can include switching the liquid chromatography system from the third configuration (III) to a fourth configuration (IV), wherein the first separation column can be fluidically connected to the separation pump and a disposal system. The method further includes directing a flow from the first separation column to the disposal system via the separation pump in the fourth configuration (IV).

[0033] In the fourth configuration (IV), the second separation column can be fluidically connected to the second pump and the detector. The method can further include directing a flow from the second separation column to the detector via the second pump in the fourth configuration (IV).

[0034] The liquid chromatography system can be switched to a third switching time (T IV ) are switched from the third configuration (III) to the fourth configuration (IV), with the third switching time (T IV ) after the second switching time (T III ) may be located.

[0035] The liquid chromatography system can be switched to a fourth switching time (T I ) from the fourth configuration (IV) back to the first configuration (I), thereby forming a cyclical process, thus ending a previous cycle and starting a subsequent cycle. The fourth switching point (T I ) can after the third switching time (T IV ) lie. A time difference t Verz ' between the fourth switching point (T I ) and the third switching point (T IV ) can be on a volume V8' of the first separation column, on a volume V verb' of fluid connections that are connected to the first separation column and are based on a flow rate F of the separation pump.

[0036] In other words, the time difference t Verz ' can correspond to the time required for a mobile phase flowing through the first separation column to traverse a volume that results from the sum of the volume of the first separation column and the fluid compounds connected to the first separation column. The time difference t Verz ' can therefore correspond to the time the mobile phase flowing through the first separation column needs to reach the detector from the second pump. It can be particularly advantageous to have such a time difference t Verz ' to be taken into account when detecting the mobile phase flowing through the second separation column with a detector, since the detector may only detect this mobile phase after a time difference t Verz with regard to the second pump starting.

[0037] The time difference t Verz ' can satisfy the following equation: tVerz'=(V8'+Vverb') / F.

[0038] At the third switching point (T IV ) the flow rate F' of the second pump can be essentially equal to the flow rate of the separation pump.

[0039] The flow rate F' of the second pump in the first configuration (I) can be considerably larger than the flow rate F of the separation pump in the first configuration (I).

[0040] The time difference t Verz can be in the range between 0 minutes and 100 minutes, preferably between 1 minute and 20 minutes, more preferably between 1 minute and 10 minutes.

[0041] The time difference t Verz ' can essentially be related to the time difference t Verz agree.

[0042] The volume V8' of the first separation column can essentially correspond to the volume V5 of the second separation column.

[0043] The volume V verb 'The fluid compounds associated with the first separation column can essentially be described by the volume V verb of fluid connections that are connected to the second separation column.

[0044] The procedure can include switching the liquid chromatography system after the fourth switching time T. I to a subsequent first switching time T II ' Switch back to the second configuration. The subsequent first switching time T II ' can after the fourth switching time T I lie. The time difference between the subsequent first switching time T II ' and the fourth switching point T I can be immediately t Verz be.

[0045] The subsequent cycle can follow the same temporal sequence, so that the times T II ', T III ', T IV ', T I ' of the following cycle, each at the times T II , T III , T IV , T I correspond to the previous cycle.

[0046] The procedure can include switching the liquid chromatography system from the first configuration (I) to the second configuration (II) by means of a controller.

[0047] The procedure can include switching the liquid chromatography system from the second configuration (II) to the third configuration (III) by means of the control.

[0048] The procedure can include switching the liquid chromatography system from the third configuration (III) to the fourth configuration (IV) by means of the control.

[0049] The procedure can include switching the liquid chromatography system from the fourth configuration (IV) to the first configuration (I) by means of the control.

[0050] The procedure can include controlling the flow rate F of the first pump, and the flow rate F' of the second pump is controlled by the controller.

[0051] The liquid chromatography system may include a pre-column switching valve. The pre-column switching valve may have a variety of ports and a variety of connecting elements for interchangeable connection of the ports, wherein one port of the pre-column switching valve may be fluidically connected to the separation pump, one port of the pre-column switching valve may be fluidically connected to the second pump, one port of the pre-column switching valve may be fluidically connected to the first separation column, and one port of the pre-column switching valve may be fluidically connected to the second separation column.

[0052] In the first configuration (I), the port of the pre-column switching valve, which can be fluidically connected to the separation pump, can be connected to the port of the pre-column switching valve, which can be fluidically connected to the first separation column. In the first configuration (I), the port of the pre-column switching valve, which can be fluidically connected to the second pump, can be fluidically connected to the port of the pre-column switching valve, which can be fluidically connected to the second separation column.

[0053] In the second configuration (II), the port of the pre-column switching valve, which may be fluidically connected to the separation pump, may be fluidically connected to the port of the pre-column switching valve, which may be fluidically connected to the second separation column. In the second configuration (II), the port of the pre-column switching valve, which may be fluidically connected to the second pump, may be fluidically connected to the port of the pre-column switching valve, which may be fluidically connected to the first separation column.

[0054] The method can switch the liquid chromatography system via the pre-column switching valve from the first configuration (I) to the second configuration (II) at the first switching time T. II include.

[0055] The method can switch the liquid chromatography system in the subsequent cycle via the pre-column switching valve from the first configuration (I) to the second configuration (II) at the subsequent first switching time T. II ' include.

[0056] In the third configuration (III), the port of the pre-column switching valve, which may be fluidically connected to the separation pump, may be fluidically connected to the port of the pre-column switching valve, which may be fluidically connected to the second separation column. In the third configuration (III), the port of the pre-column switching valve, which may be fluidically connected to the second pump, may be fluidically connected to the port of the pre-column switching valve, which may be fluidically connected to the first separation column in the third configuration (III).

[0057] In the fourth configuration (IV), the port of the pre-column switching valve, which can be fluidically connected to the separation pump, can be fluidically connected to the port of the pre-column switching valve, which can be fluidically connected to the first separation column. In the fourth configuration (IV), the port of the pre-column switching valve, which can be fluidically connected to the second pump, can be fluidically connected to the port of the pre-column switching valve, which can be fluidically connected to the second separation column.

[0058] The method can switch the liquid chromatography system via the pre-column switching valve from the third configuration (III) to the fourth configuration (IV) at the third switching time T. IV include.

[0059] The method can switch the liquid chromatography system via the pre-column switching valve in the subsequent cycle from the third configuration (III) to the fourth configuration (III) at the subsequent third switching time T. IV ' include.

[0060] The switching of the liquid chromatography system from the first configuration (I) to the second configuration (II) via the pre-column switching valve can be controlled by the controller.

[0061] The switching of the liquid chromatography system from the third configuration (III) to the fourth configuration (IV) via the pre-column switching valve can be controlled by the control unit.

[0062] The liquid chromatography system can include a post-column switching valve. The post-column switching valve can have a variety of ports and a variety of connecting elements for interchangeable connection of the ports, wherein one port of the post-column switching valve can be fluidically connected to the first separation column, one port of the post-column switching valve can be fluidically connected to the second separation column, one port of the post-column switching valve can be fluidically connected to the waste disposal system, and one port of the post-column switching valve can be fluidically connected to the detector.

[0063] In the first configuration (I), the port of the post-column switching valve, which can be fluidically connected to the first separation column, can be fluidically connected to the port of the post-column switching valve, which can be fluidically connected to the detector. In the first configuration (I), the port of the post-column switching valve, which can be fluidically connected to the second separation column, can be fluidically connected to the port of the post-column switching valve, which can be fluidically connected to the disposal system.

[0064] In the second configuration (II), the port of the post-column switching valve, which may be fluidically connected to the first separation column, may be fluidically connected to the port of the post-column switching valve, which may be fluidically connected to the detector. In the second configuration (II), the port of the post-column switching valve, which may be fluidically connected to the second separation column, may be fluidically connected to the port of the post-column switching valve, which may be fluidically connected to the disposal system.

[0065] In the third configuration (III), the port of the post-column switching valve, which may be fluidically connected to the first separation column, may be fluidically connected to the port of the post-column switching valve, which may be fluidically connected to a disposal point. In the third configuration (III), the port of the post-column switching valve, which may be fluidically connected to the second separation column, may be fluidically connected to the port of the post-column switching valve, which may be fluidically connected to the detector.

[0066] The method can switch the liquid chromatography system via the post-column switching valve from the second configuration (II) to the third configuration (III) at the second switching time T. III include.

[0067] The method can switch the liquid chromatography system in the subsequent cycle via the post-column switching valve from the second configuration (II) to the third configuration (III) at the following second switching time T. III ' include.

[0068] In the fourth configuration (IV), the port of the post-column switching valve, which may be fluidically connected to the first separation column, may be fluidically connected to the port of the post-column switching valve, which in the fourth configuration (IV) may be fluidically connected to a disposal point. In the fourth configuration (IV), the port of the post-column switching valve, which may be fluidically connected to the second separation column, may be fluidically connected to the port of the post-column switching valve, which may be fluidically connected to the detector.

[0069] The method can switch the liquid chromatography system via the post-column switching valve from the fourth configuration (IV) to the first configuration (I) at the fourth switching time T. I include.

[0070] The method can switch the liquid chromatography system in the subsequent cycle via the post-column switching valve from the fourth configuration (IV) to the first configuration (I) at the subsequent fourth switching time T. I ' include.

[0071] The switching of the liquid chromatography system from the second configuration (II) to the third configuration (III) via the post-column switching valve can be controlled by the controller.

[0072] The switching of the liquid chromatography system from the fourth configuration (IV) to the first configuration (I) via the post-column switching valve can be controlled by the controller.

[0073] t Verzcan essentially be defined by a cavity volume of a separation column V Säule and volumes of the fluidic compounds V verb between the separation column and the upstream and downstream switching valves and the flow rate of a gradient f Grad can be defined. Therefore, t Verz This is the time required for the liquid fraction, which represents a solvent composition at the beginning of the gradient, to actually pass through the separation column and reach the post-column valve.

[0074] The liquid chromatography system can include a double-tube electrospray source, wherein the double-tube electrospray source comprises a first tube with the first separation column and a second tube with the second separation column.

[0075] An end section of the first tube can include a first emitter, with the first emitter configured to spray into the detector, and an end section of the second tube can include a second emitter, with the second emitter configured to spray into the detector.

[0076] Regarding the double-tube electrospray configuration, the following should be noted: When a high voltage is applied to one of the tubes (e.g., the first tube containing the first separation column), this tube sprays into the detector, e.g., a mass spectrometer. Thus, particles passing through this tube reach the detector, and this is assumed to be achieved through a fluid connection between the corresponding separation column and the detector.

[0077] Furthermore, if the tube is not subjected to a sufficiently high voltage, the particles from the tube will not reach the detector. They therefore cannot be analyzed further and are lost to the process. For example, the liquid in question may simply evaporate. In this description, this is achieved by connecting the respective tube / column to the waste disposal system via a fluidic connection.

[0078] The detector may include a mass spectrometry detector.

[0079] In the first configuration (I), the first tube can be enabled to spray from the first emitter into the detector by applying a high voltage to the first tube in the first configuration (I).

[0080] In the second configuration (II), the first tube can be enabled to spray from the first emitter into the detector by applying a high voltage to the first tube in the second configuration (II).

[0081] In the third configuration (III), the second tube can be enabled to spray from the second emitter into the detector by applying a high voltage to the second tube in the third configuration (III).

[0082] In the fourth configuration (IV), the second tube can be enabled to spray from the second emitter into the detector by applying a high voltage to the second tube in the fourth configuration (IV).

[0083] The high voltage can be in a range between 1 kV and 5 kV.

[0084] Electrospray ionization (ESI) involves applying a high voltage to generate a fine aerosol of charged droplets from a liquid sample. The high voltage typically used for ESI ranges from 1 kV to 5 kV. This voltage range is sufficient to induce ionization of the sample and produce the charged droplets for mass spectrometric analysis. The exact voltage used can vary depending on the specific instrument and the type of sample being analyzed.

[0085] The method can switch the liquid chromatography system from the second configuration (II) to the third configuration (III) at the second switching time T. III by switching from the first tube, which is enabled to spray from the first emitter into the detector, to the second tube, which is enabled to spray from the second emitter into the detector.

[0086] The method can switch the liquid chromatography system from the second configuration (II) to the third configuration (III) at the subsequent second switching time T. III ' in the subsequent cycle by switching from the first tube, which is enabled to spray from the first emitter into the detector, to the second tube, which is enabled to spray from the second emitter into the detector.

[0087] The method can switch the liquid chromatography system from the fourth configuration (IV) to the first configuration (I) at the fourth switching time (T I ) by switching from the second tube, which is enabled to spray from the second emitter into the detector, to the first tube, which is enabled to spray from the first emitter into the detector.

[0088] The method can switch the liquid chromatography system from the fourth configuration (IV) to the first configuration (I) at the subsequent fourth switching time T. I ' in the subsequent cycle by switching from the second tube, which is enabled to spray from the second emitter into the detector, to the first tube, which is enabled to spray from the first emitter into the detector.

[0089] The liquid chromatography system can include an injection valve. The injection valve can have multiple ports and connecting elements. One port of the injection valve can be fluidically connected to the second pump, and another port can be fluidically connected to a port on the pre-column switching valve. The method can involve fluidically connecting the port of the injection valve that can be fluidically connected to the second pump to the port of the injection valve that can be fluidically connected to the pre-column switching valve.

[0090] The injection valve may further comprise a variety of ports. The method may involve fluidically connecting these additional ports to a variety of sample containers, each containing a variety of samples.

[0091] The procedure may involve injecting a sample from a sample container into the liquid chromatography system via the injection valve.

[0092] The procedure may include establishing a sample flow from the injection valve to the pre-column switching valve using the second pump.

[0093] The procedure may include switching from injecting a sample from one sample container into the liquid chromatography system via the injection valve to injecting a different sample from another sample container into the liquid chromatography system via the injection valve.

[0094] The switch from injecting a sample from one sample container into the liquid chromatography system via the injection valve to injecting another sample from a different sample container into the liquid chromatography system via the injection valve can be performed at the first switching time (T II) take place.

[0095] Switching from injecting a sample from one sample container into the liquid chromatography system via the injection valve to injecting a different sample from another sample container into the liquid chromatography system via the injection valve can be performed at the following first switching time (T II ') in the following cycle.

[0096] The switch from injecting a sample from one sample container into the liquid chromatography system via the injection valve to injecting a different sample from another sample container into the liquid chromatography system via the injection valve can be performed at the third switching time (T IV ) take place.

[0097] The switch from injecting a sample from one sample container into the liquid chromatography system via the injection valve to injecting another sample from a different sample container into the liquid chromatography system via the injection valve can be performed at the following third switching time (T IV ') in the following cycle.

[0098] The injection of a sample from one sample container into the liquid chromatography system via the injection valve can be controlled by the controller. Switching from injecting a sample from one sample container into the liquid chromatography system via the injection valve to injecting a different sample from a different sample container into the liquid chromatography system via the injection valve can also be controlled by the controller.

[0099] The procedure can initiate the provision of a gradient by the separation pump at the first switching time (T II The procedure can include stopping the supply of a gradient by the separation pump at a time T. Grad. Stopp include the time T Grad. Stopp can after the second switching time T III lie. The time T Grad. Stopp can occur before the third switching time T IV lay.

[0100] The procedure can initiate the provision of a gradient by the separation pump at the third switching time (T IV The procedure can include stopping the supply of a gradient by the separation pump at a time T. Grad. Stopp ' include. The time T Grad. Stopp ' can after the fourth switching time T II lie. The time T Grad. Stopp ' can occur before the subsequent first switching time T II ' in the following cycle.

[0101] The procedure can include controlling the start and stop of gradient provisioning.

[0102] At the first switching time (T II ) a solvent composition supplied by the second pump can be essentially identical to a solvent composition supplied by the separation pump.

[0103] At the third switching point (T IV ) a solvent composition supplied by the second pump can be essentially identical to a solvent composition supplied by the separation pump.

[0104] The method can start the detection using a detector at the second switching time (T III ) comprising, wherein the method involves stopping the detection by means of the detector at a detector stop time T Det. Stopp includes the detector stop time T Det. Stopp can after the third switching time TIV lie. The detector stop time T Det. Stopp can occur before the fourth switching time T I lay.

[0105] The method can start the detection using the detector at the fourth switching time T. I The method can include stopping the detection using the detector at a further detector stop time T. Det. Stopp ' include. The time of further detector stop time T Det. Stopp ' lies after the subsequent first switching time T II ' in the following cycle. The next detector stop time T Det. Stopp ' lies before the subsequent second switching point T III ' in the following cycle.

[0106] The time differences between any times according to embodiments of the present invention, i.e., the time at which the provision of a gradient can be started, the time at which the provision of a gradient can be stopped, the time at which the detection can be started, and the time at which the detection can be stopped, can be advantageous for at least the following reasons.

[0107] Embodiments of the present invention relate, at least in part, to a workflow in which the time difference between the start of the gradient feed and the start of detection differs significantly from zero. This may not be the case with prior art liquid chromatography systems. In a general liquid chromatography system comprising at least one separation pump, a separation column, and a detector, a mobile phase may require a certain amount of time to traverse a separation column. This time may, in turn, depend on the volume of the separation column as well as on the fluid connection that links the separation column to the pump and the separation column to the detector. In other words, the gradient feed at the separation pump may differ from the gradient feed at the detector at a given time.For example, if the gradient feed from the separation pump is just starting, the gradient feed at the pump is equal to the initial gradient feed, while the gradient feed at the detector will later equal the initial gradient feed. In many prior art tandem liquid chromatography systems, the detector can be configured to start the detection window when the pump starts feeding the gradient into the separation column. However, such a workflow can hinder optimal use of the detector's detection window because the detector may already be actively used from the moment the pump starts feeding the gradient. In other words, the detector may be actively used from the moment the gradient feed at the separation pump equals the initial gradient, rather than when the gradient feed at the detector equals the initial gradient.As a result, the detector may, for example, actively record before the gradient feed to the detector establishes the starting gradient. Consequently, chromatogram storage space may be used for data that may not be related to the sample(s) of interest. In many prior art tandem liquid chromatography systems, where the detector may be configured so that the detection window starts when the pump begins feeding the gradient to a column, a fraction of the chromatographic peaks of the compound(s) of interest may be missing from the chromatograms. Furthermore, the chromatogram may contain chromatographic peaks that are partly attributable to compounds eluted from one column and partly to those from another.

[0108] The method of the present invention can include controlling the start of the detection and the stopping of the detection can be controlled by the control.

[0109] The procedure may include the use of an optimization procedure to determine the time difference t. Verz and / or the time difference t Verz ' to optimize.

[0110] This can be particularly advantageous with regard to at least some prior art technologies for at least the following reasons. Embodiments of the present invention relate at least partially to a workflow in which the time difference between the start of gradient injection and the start of detection differs significantly from zero and can be optimized. More generally, embodiments of the present invention relate at least partially to the optimization of a tandem liquid chromatography system. Embodiments of the present invention relate at least partially to the optimization of a tandem liquid chromatography system and to ensuring, among other things, an increase in throughput and / or consistent and reproducible chromatographic results and analyses and / or limited data storage space usage.

[0111] The procedure can include at least partially controlling the steps contained in the optimization procedure.

[0112] The process may include, at least partially, the use of a user interface in the steps of the optimization procedure.

[0113] The procedure may include the acquisition of a reference chromatogram.

[0114] The procedure may include the acquisition of a reference chromatogram containing at least some of the characteristic chromatographic peaks of a sample.

[0115] The procedure may include capturing the reference by performing a linear gradient elution followed by an isocratic phase.

[0116] In other words, an optimization of t VerzThey can be employed using different methods. In some embodiments, a reference run (i.e., an exploratory run) can be performed to obtain a reference chromatogram containing all relevant peaks characteristic of the sample being analyzed. This reference can be obtained by performing an LC sample run that is not optimized for maximum throughput using tandem LC. For example, a linear gradient followed by an isocratic phase can be performed. Based on this reference chromatogram, the actual tandem LC workflow can be adjusted by adapting t Verz to be optimized.

[0117] The optimization procedure may include the execution of an automatic optimization procedure.

[0118] The step of acquiring a reference chromatogram can precede the step of executing the automatic optimization procedure.

[0119] The automatic optimization procedure can adjust the time difference t. Verz and adjusting the time difference t Verz ' include.

[0120] The procedure may involve performing the fitting by iterating the fitting, whereby the iteration may be carried out until the number of detectable peaks or detectable compounds in a obtained chromatogram is maximized.

[0121] The procedure may include comparing the number of detectable peaks or detectable compounds in the obtained chromatogram with the number of detectable peaks or detectable compounds in the reference chromatogram.

[0122] The method may involve comparing the number of detectable peaks or detectable compounds in a obtained chromatogram with the number of detectable peaks or detectable compounds in a reference chromatogram, which may be provided externally.

[0123] The detectable peaks or compounds may correspond to peptides, proteins and / or other biomolecules.

[0124] The procedure may include performing the fitting by iterating the fitting, whereby the iteration may be carried out by comparing the peaks in a obtained chromatogram with the peaks in the reference chromatogram until a maximum match with the reference chromatogram is achieved.

[0125] The procedure may include performing the fitting by iterating the fitting, wherein the iteration may be carried out by comparing the peaks in a obtained chromatogram with the peaks in the reference chromatogram until a maximum match with the reference chromatogram is achieved, and wherein this reference chromatogram may be provided externally.

[0126] The procedure may include performing the fitting by iterating the fitting, wherein the iteration may be performed at least partially until the number of detectable peaks or detectable compounds in a obtained chromatogram is maximized, and may be performed at least partially by comparing the peaks in a obtained chromatogram with the peaks in the reference chromatogram until maximum agreement with the reference chromatogram is achieved.

[0127] The method may include performing the fitting by iterating the fitting, wherein the iteration may be performed at least partially until the number of detectable peaks or detectable compounds in a obtained chromatogram is maximized, and at least partially by comparing the peaks in a obtained chromatogram with the peaks in a reference chromatogram until maximum agreement with the reference chromatogram is achieved, wherein this reference chromatogram may be provided externally.

[0128] The procedure may include the use of peak threshold detection algorithms for the detection and / or comparison of peaks.

[0129] The method may include the use of peak threshold detection based on peak height or signal height.

[0130] The method may include the use of peak threshold detection based on the peak area or signal area.

[0131] The procedure may include the use of peak threshold detection based on peak detection algorithms used in the coding sequence.

[0132] The procedure may include the use of peak threshold detection algorithms based on machine learning techniques.

[0133] The optimization procedure may include at least partial use of a manual optimization procedure.

[0134] Overall, the procedure can include an automated optimization process that uses a software-driven approach, where the chromatogram can be iteratively optimized by t VerzThe chromatogram can be adjusted with respect to one or more of the following conditions: (1) All potentially detectable peaks can be included in the optimized chromatogram: The chromatogram can be optimized based on the number of detectable peaks or compounds (e.g., identified peptides, proteins, etc.). (2) The chromatogram can be optimized based on the greatest similarity to the reference chromatogram.

[0135] For this purpose, threshold values ​​(based on peak / signal height or area) similar to the peak detection algorithm used in state-of-the-art CDSs, as well as machine learning techniques, can be used.

[0136] The step of acquiring a reference chromatogram can precede the step of at least partially using the manual optimization procedure.

[0137] The manual optimization procedure may involve a user manually defining a detection window, which can encompass the time from the start of detection to the end of detection. The user also manually defines the first and last eluted compounds that should be present in an optimized chromatogram. The optimized chromatogram may consist of the chromatogram obtained at the end of the optimization procedure.

[0138] The user's definition of the detection window can include manually cropping a section of interest from a obtained chromatogram, where the defined detection window can be based on the section of interest of the obtained chromatogram and where the cropping can be performed on a dedicated user interface.

[0139] A mass spectrometer and / or a diode array detector and / or another peak detection instrument can be used by the user to determine the first and last eluted compound that may be present in the optimized chromatogram.

[0140] The manual optimization procedure can involve manually adjusting the time difference t. Verz and the time difference t Verz ' by the user, with the control system automatically optimizing the rest of the workflow.

[0141] The manual optimization procedure can involve manually adjusting the time difference t. Verz and the time difference t Verz ' by the user, whereby the user can manually adjust the rest of a workflow.

[0142] Overall, the procedure can include a manual and / or user-based optimization process, for example, according to the following features: (1) A user can manually define a detection window, e.g., in a dedicated user interface by manually cropping it to the chromatogram section of interest. Visual aids can be provided for this purpose. (2) A user can define first and last eluting compounds that can be included in the optimized chromatogram. Peak detection capabilities (such as those of a mass spectrometer or a diode array detector) can be used for this purpose. (3) A user can specify a delay time and adjust this parameter in an input field of a dedicated user interface for a tandem workflow. The workflow can be automatically programmed to take the delay time into account.(4) A user can manually determine the delay time and the workflow, taking the delay time into account.

[0143] The flow from the first separation column to the detector in the first configuration (I) can have a flow rate in the range of 0 to 10 ml / min, preferably 0 to 100 µl / min, such as 0.1 to 10 µl / min.

[0144] The flow from the second separation column to disposal can have a flow rate in the range of 0 to 10 ml / min, preferably 0 to 100 µl / min, such as 0.1 to 10 µl / min.

[0145] The pressure provided by the separation pump can be in the range of 100 bar to 2,000 bar, preferably 200 bar to 1,500 bar, such as 500 bar to 1,500 bar.

[0146] The process may include optimizing solvent supply.

[0147] Optimizing solvent supply can include optimizing a solvent composition at the start of a gradient supply.

[0148] Optimizing solvent supply can involve optimizing a solvent composition at the end of a gradient supply.

[0149] Optimizing the solvent supply can include optimizing the slope of a gradient supply.

[0150] This means that, in addition to shifting the position of the elution window over time, the size of the elution window can also be optimized, for example by adjusting the solvent composition at the start (%Bstart) and end (%Bend) of the gradient or the slope in parts of the gradient. Methods for this are also described in DE 10 2019 111783 A1, to which reference is hereby made in its entirety.

[0151] In another aspect, the present invention relates to a liquid chromatography system. The system comprises: a first separation column, a separation pump, and a detector. The first separation column is configured to be fluidically connected to the separation pump and the detector in a first configuration (I), wherein the system is configured to direct a flow from the first separation column to the detector by means of the separation pump in the first configuration (I). The system is configured to switch from the first configuration (I) to a second configuration (II), wherein the first separation column is configured to be fluidically connected to the second pump and the detector in the second configuration (II), and the system is configured to direct a flow from the first separation column to the detector by means of the second pump in the second configuration (II).

[0152] The system can further include a second separation column and a disposal system. The second separation column can be configured to be fluidically connected to the second pump and the disposal system in the first configuration (I), and the system can be configured to direct a flow from the second separation column to the disposal system via the second pump in the first configuration (I).

[0153] The second separation column can be configured to be fluidically connected to the separation pump and the disposal in the second configuration (II); the system can be configured to direct a flow from the second separation column to the disposal via the separation pump in the second configuration (II).

[0154] The system can be configured to switch from the second configuration (II) to a third configuration (III), where the first separation column is configured to be fluidically connected to the second pump and a disposal, and the system can be configured to direct a flow from the first separation column to the disposal in the third configuration (III) using the second pump.

[0155] In the third configuration (III), the second separation column can be configured to be fluidically connected to the separation pump and the detector, and the system can further be configured to direct a flow from the second separation column to the detector in the third configuration (III) by means of the separation pump.

[0156] The system can be configured to switch at a first switching time (T II ) to switch from the first configuration (I) to the second configuration (II).

[0157] The system can be configured to switch at a second time (T III ) to switch from the second configuration (II) to the third configuration, where the second switching time (T III ) after the first switching time (T II ) lies.

[0158] A time difference t Verz between the second switching time (T III ) and the first switching time (T II ) can be applied to a volume V5 of the second separation column, to a volume V verb of fluid connections connected to the second separation column and based on a flow rate F of the separation pump.

[0159] The time difference t Verz can satisfy the following equation: t Verz = (V5 + V verb ) / F.

[0160] The time difference t Verz can be in the range between 0 minutes and 100 minutes, preferably between 1 minute and 20 minutes, more preferably between 1 minute and 10 minutes.

[0161] At the first switching time (T II ) the flow rate F' of the second pump can be essentially equal to the flow rate F of the separation pump.

[0162] A flow rate F' of the second pump in the third configuration (III) can be considerably larger than the flow rate F of the separation pump in the third configuration (III).

[0163] The system can be configured to switch from the third configuration (III) to a fourth configuration (IV), in which the first separation column is fluidically connected to the separation pump and a disposal, and the system can be configured to direct a flow from the first separation column to the disposal via the separation pump in the fourth configuration (IV).

[0164] In the fourth configuration (IV), the second separation column can be fluidically connected to the second pump and the detector, and the system can be configured to direct a flow from the second separation column to the detector via the second pump in the fourth configuration (IV).

[0165] The system can be configured to switch at a third time (T IV ) to switch from the third configuration (III) to the fourth configuration (IV), with the third switching time (T IV ) after the second switching time (T III ) lies.

[0166] The system can be configured to switch at a fourth time (T I ) to switch from the fourth configuration (IV) back to the first configuration (I), thereby forming a cyclic process and thereby ending a previous cycle and starting a subsequent cycle, with the fourth switching point (T I) after the third switching point (T IV ) lies and where a time difference t Verz ' between the fourth switching point (T I ) and the third switching point (T IV ) on a volume V8' of the first separation column, on a volume V verb ' of fluid connections connected to the first separation column, and based on a flow rate F of the separation pump.

[0167] The time difference t Verz ' can satisfy the following equation: t Verz ' = (V8' + V verb ') / F.

[0168] At the third switching point (T IV ) the flow rate F' of the second pump can be essentially equal to the flow rate of the separation pump.

[0169] The flow rate F' of the second pump in the first configuration (I) can be considerably larger than the flow rate F of the separation pump in the first configuration (I).

[0170] The time difference t Verzcan be in the range between 0 minutes and 100 minutes, preferably between 1 minute and 20 minutes, more preferably between 1 minute and 10 minutes.

[0171] The time difference t Verz ' can essentially be related to the time difference t Verz agree.

[0172] The volume V8' of the first separation column can essentially correspond to the volume V5 of the second separation column.

[0173] The volume V verb 'The fluid compounds associated with the first separation column can essentially be described by the volume V verb of fluid connections that are connected to the second separation column.

[0174] The system can be used after the fourth switching time T I be configured to start the system at a subsequent first switching time T II ' to switch back to the second configuration, where the subsequent first switching time T II' after the fourth switching point T I lies and where the time difference between the subsequent first switching time T II ' and the fourth switching point T I equal to t Verz is.

[0175] The subsequent cycle can follow the same temporal sequence, so that the times T II ', T III ', T IV ', T I ' of the following cycle, each at the times T II , T III , T IV , T I correspond to the previous cycle.

[0176] The system can include a controller and the system can be configured to switch from the first configuration (I) to the second configuration (II) using the controller.

[0177] The system can be configured to switch from the second configuration (II) to the third configuration (III) using the controller.

[0178] The system can be configured to switch from the third configuration (III) to the fourth configuration (IV) using the controller.

[0179] The system can be configured to switch from the fourth configuration (IV) to the first configuration (I) using the controller.

[0180] The system can be configured to control the flow rate F of the first pump and the flow rate F' of the second pump via the controller.

[0181] The liquid chromatography system can include a pre-column switching valve, wherein the pre-column switching valve comprises a plurality of ports and a plurality of connecting elements for interchangeably connecting the ports, wherein one port of the pre-column switching valve is fluidically connected to the separation pump, one port of the pre-column switching valve is fluidically connected to the second pump, one port of the pre-column switching valve is fluidically connected to the first separation column, and one port of the pre-column switching valve is fluidically connected to the second separation column.

[0182] In the first configuration (I), the port of the pre-column switching valve, which is fluidically connected to the separation pump, can be connected to the port of the pre-column switching valve, which is fluidically connected to the first separation column, and in the first configuration (I), the port of the pre-column switching valve, which is fluidically connected to the second pump, can be fluidically connected to the port of the pre-column switching valve, which is fluidically connected to the second separation column.

[0183] In the second configuration (II), the port of the pre-column switching valve that is fluidically connected to the separation pump can be fluidically connected to the port of the pre-column switching valve that is fluidically connected to the second separation column, and in the second configuration (II), the port of the pre-column switching valve that is fluidically connected to the second pump can be fluidically connected to the port of the pre-column switching valve that is fluidically connected to the first separation column.

[0184] The system can be configured to use the upstream column switching valve at the first switching time T. II to switch from the first configuration (I) to the second configuration (II).

[0185] The system can be configured to use the upstream column switching valve in the subsequent cycle at the following first switching time T. II ' to switch from the first configuration (I) to the second configuration (II).

[0186] In the third configuration (III), the port of the pre-column switching valve, which is fluidically connected to the separation pump, can be fluidically connected to the port of the pre-column switching valve, which is fluidically connected to the second separation column, and in the third configuration (III), the port of the pre-column switching valve, which is fluidically connected to the second pump, can be fluidically connected to the port of the pre-column switching valve, which is fluidically connected to the first separation column, in the third configuration (III).

[0187] In the fourth configuration (IV), the port of the pre-column switching valve that is fluidically connected to the separation pump can be fluidically connected to the port of the pre-column switching valve that is fluidically connected to the first separation column, and in the fourth configuration (IV), the port of the pre-column switching valve that is fluidically connected to the second pump can be fluidically connected to the port of the pre-column switching valve that is fluidically connected to the second separation column.

[0188] The system can be configured to use the upstream column switching valve at the third switching time T. IV to switch from the third configuration (III) to the fourth configuration (IV).

[0189] The system can be configured to use the upstream column switching valve in the subsequent cycle at the following third switching time T. IV ' to switch from the third configuration (III) to the fourth configuration (III).

[0190] The system can be configured to control the switch from the first configuration (I) to the second configuration (II) via the upstream column switching valve through the controller.

[0191] The system can be configured to control the switching of the system from the third configuration (III) to the fourth configuration (IV) via the pre-column switching valve by the controller.

[0192] The system can include a post-column switching valve, wherein the post-column switching valve comprises a plurality of ports and a plurality of connecting elements for interchangeably connecting the ports, wherein one port of the post-column switching valve is fluidically connected to the first separation column, one port of the post-column switching valve is fluidically connected to the second separation column, one port of the post-column switching valve is fluidically connected to the disposal, and one port of the post-column switching valve is fluidically connected to the detector.

[0193] In the first configuration (I), the port of the post-column switching valve that is fluidically connected to the first separation column can be fluidically connected to the port of the post-column switching valve that is fluidically connected to the detector, and in the first configuration (I), the port of the post-column switching valve that is fluidically connected to the second separation column can be fluidically connected to the port of the post-column switching valve that is fluidically connected to the disposal.

[0194] In the second configuration (II), the port of the post-column switching valve that is fluidically connected to the first separation column can be fluidically connected to the port of the post-column switching valve that is fluidically connected to the detector, and in the second configuration (II), the port of the post-column switching valve that is fluidically connected to the second separation column can be fluidically connected to the port of the post-column switching valve that is fluidically connected to the disposal.

[0195] In the third configuration (III), the port of the post-column switching valve that is fluidically connected to the first separation column can be fluidically connected to the port of the post-column switching valve that is fluidically connected to a disposal, and in the third configuration (III), the port of the post-column switching valve that is fluidically connected to the second separation column can be fluidically connected to the port of the post-column switching valve that is fluidically connected to the detector.

[0196] The system can be configured to switch at the second switching time T III to switch from the second configuration (II) to the third configuration (III) via the post-column switching valve.

[0197] The system can be configured to switch to the second switching time T in the subsequent cycle. III' to switch from the second configuration (II) to the third configuration (III) via the post-column switching valve.

[0198] In the fourth configuration (IV), the port of the post-column switching valve that is fluidically connected to the first separation column can be fluidically connected to the port of the post-column switching valve that is fluidically connected to a disposal in the fourth configuration (IV); in the fourth configuration (IV), the port of the post-column switching valve that is fluidically connected to the second separation column can be fluidically connected to the port of the post-column switching valve that is fluidically connected to the detector.

[0199] The system can be configured to use the post-column switching valve at the fourth switching time T I to switch from the fourth configuration (IV) to the first configuration (I).

[0200] The system can be configured to use the downstream column switching valve in the subsequent cycle at the following fourth switching time T. I ' to switch from the fourth configuration (IV) to the first configuration (I).

[0201] The system can be configured to switch from the second configuration (II) to the third configuration (III) via the post-column switching valve, controlled by the controller.

[0202] The system can be configured to control the switch from the fourth configuration (IV) to the first configuration (I) via the post-column switching valve through the controller.

[0203] The system can include a double-tube electrospray source, wherein the double-tube electrospray source comprises a first tube comprising the first separation column and a second tube comprising the second separation column.

[0204] An end section of the first tube can include a first emitter, with the first emitter configured to spray into the detector, and a second end section of the second tube can include a second emitter, with the second emitter configured to spray into the detector.

[0205] The detector may include a mass spectrometry detector.

[0206] The system can be configured to enable the first tube to spray from the first emitter into the detector in the first configuration (I) by applying a high voltage to the first tube in the first configuration (I).

[0207] The system can be configured to enable the first tube to spray from the first emitter into the detector in the second configuration (II) by applying a high voltage to the first tube in the second configuration (II).

[0208] The system can be configured to enable the second tube to spray from the second emitter into the detector in the third configuration (III) by applying a high voltage to the second tube in the third configuration (III).

[0209] The system can be configured to enable the second tube to spray from the second emitter into the detector in the fourth configuration (IV) by applying a high voltage to the second tube in the fourth configuration (IV).

[0210] The high voltage can be in a range between 1 kV and 5 kV.

[0211] The system can be configured to switch at the second switching time T IIIto switch from the second configuration (II) to the third configuration (III) by switching from the first tube, which is enabled to spray from the first emitter into the detector, to the second tube, which is enabled to spray from the second emitter into the detector.

[0212] The system can be configured to switch to the second switching time T in the subsequent cycle. III ' to switch from the second configuration (II) to the third configuration (III) by switching from the first tube, which is enabled to spray from the first emitter into the detector, to the second tube, which is enabled to spray from the second emitter into the detector.

[0213] The system can be configured to switch at the fourth switching time (T I) to switch from the fourth configuration (IV) to the first configuration (I) by switching from the second tube, which is enabled to spray from the second emitter into the detector, to the first tube, which is enabled to spray from the first emitter into the detector.

[0214] The system can be configured to operate at the subsequent fourth switching time T I ' in the following cycle to switch from the fourth configuration (IV) to the first configuration (I) by switching from the second tube, which is enabled to spray from the second emitter into the detector, to the first tube, which is enabled to spray from the first emitter into the detector.

[0215] The system can include an injection valve, wherein the injection valve comprises a plurality of ports and a plurality of connecting elements, and wherein one port of the injection valve is fluidically connected to the second pump, one port of the injection valve is fluidically connected to a port of the upstream switching valve, and the system can be configured to connect the port of the injection valve that is fluidically connected to the second pump to the port of the injection valve that is fluidically connected to the upstream switching valve.

[0216] The injection valve may further include a variety of ports, and the system may be configured to fluidically connect the other variety of ports to a variety of sample containers containing a variety of samples.

[0217] The system can be configured to inject a sample from a sample container into the liquid chromatography system via the injection valve.

[0218] The system can be configured to use the second pump to create a sample flow from the injection valve to the pre-column switching valve.

[0219] The system can be configured to switch from injecting one sample from one sample container into the system via the injection valve to injecting another sample from a different sample container into the system via the injection valve.

[0220] The switch from injecting a sample from one sample container into the system via the injection valve to injecting a different sample from another sample container into the liquid chromatography system via the injection valve can be performed at the first switching time (T II ) take place.

[0221] The switch from injecting a sample from one sample container into the system via the injection valve to injecting another sample from a different sample container into the liquid chromatography system via the injection valve can be performed at the following first switching time (T II ') in the following cycle.

[0222] The switch from injecting a sample from one sample container into the system via the injection valve to injecting a different sample from another sample container into the liquid chromatography system via the injection valve can be performed at the third switching time (T IV ) take place.

[0223] The switch from injecting a sample from one sample container into the system via the injection valve to injecting another sample from a different sample container into the liquid chromatography system via the injection valve can be performed at the following third switching time (TIV ') in the following cycle.

[0224] The system can be configured to control the injection of a sample from one sample container into the system via the injection valve by the controller, and the system can be configured to control the switching from injecting one sample from one sample container into the system via the injection valve to injecting another sample from another sample container into the system via the injection valve by the controller.

[0225] The system can be configured to provide a gradient through the separation pump at the first switching time (T II ) to start, and the system can be configured to provide a gradient through the separation pump at a time T Grad. Stopp to stop, with time T Grad. Stopp after the second switching time T III lies and where time T Grad. Stoppbefore the third switching point T IV lies.

[0226] The system can be configured to provide a gradient through the separation pump at the third switching time (T IV ) to start, and the system can be configured to provide a gradient through the separation pump at a time T Grad. Stopp ' to stop, with the time T Grad. Stopp ' after the fourth switching point T II lies and where time T Grad. Stopp ' before the subsequent first switching time T II ' lies in the following cycle.

[0227] The system can be configured to control the start and end of gradient provisioning.

[0228] At the first switching time (T II) a solvent composition supplied by the second pump can be essentially identical to a solvent composition supplied by the separation pump.

[0229] At the third switching point (T IV ) a solvent composition supplied by the second pump can be essentially identical to a solvent composition supplied by the separation pump.

[0230] The system can be configured to detect using a detector at the second switching time (T III ) to start, and the system can be configured to start detection using the detector at a detector stop time T Det. Stopp to stop, with the detector stop time T Det. Stopp after the third switching point T IV lies, where the detector stop time T Det. Stopp before the fourth switching point T I lies.

[0231] The system can be configured to detect using the detector at the fourth switching time T. I to start, and the system can be configured to start detection using the detector at a further detector stop time T. Det. Stopp ' to stop, whereby the further detector stopping time T Det. Stopp ' after the subsequent first switching time T II ' in the following cycle, where the further detector stop time T Det. Stopp ' before the subsequent second switching point T III ' lies in the following cycle.

[0232] The system can be configured to allow the controller to control the start and end of detection.

[0233] The system can be configured to use an optimization procedure to calculate the time difference t. Verz and / or the time difference t Verz ' to optimize.

[0234] The system can be configured to control at least some of the steps included in the optimization procedure through the control system.

[0235] The system may include a user interface.

[0236] The system can be configured to use the user interface, at least partially, in the steps of the optimization procedure.

[0237] The system can be configured to acquire a reference chromatogram.

[0238] The system can be configured to capture a reference chromatogram that contains at least some of the characteristic chromatographic peaks of a sample.

[0239] The system can be configured to acquire the reference by performing a linear gradient elution followed by an isocratic phase.

[0240] The optimization procedure may include the execution of an automatic optimization procedure, and the system may be configured to execute the automatic optimization procedure.

[0241] The system can be configured to perform the step of acquiring a reference chromatogram before the step of executing the automatic optimization procedure.

[0242] The automatic optimization procedure can adjust the time difference t. Verz and the adjustment of the time difference t Verz ' include, and the system can be configured to adjust for the time difference t Verz and the adjustment of the time difference t Verz ' to carry out.

[0243] The system can be configured to perform the adjustment by iterating the adjustment, and the system can be configured to perform the iteration until the number of detectable peaks or detectable compounds in a obtained chromatogram is maximized.

[0244] The system can be configured to compare the number of detectable peaks or detectable compounds in the obtained chromatogram with the number of detectable peaks or detectable compounds in the reference chromatogram.

[0245] The system can be configured to compare the number of detectable peaks or detectable compounds in a obtained chromatogram with the number of detectable peaks or detectable compounds in a reference chromatogram, where this reference chromatogram is provided externally.

[0246] The detectable peaks or compounds may correspond to peptides, proteins and / or other biomolecules.

[0247] The system can be configured to perform the fitting by iterating the fitting process, and the system can be configured to perform the iteration by comparing the peaks in a obtained chromatogram with the peaks in the reference chromatogram until maximum agreement with the reference chromatogram is achieved.

[0248] The system can be configured to perform the fitting by iterating the fitting, and the system can be configured to perform the iteration by comparing the peaks in a obtained chromatogram with the peaks in the reference chromatogram until a maximum match with the reference chromatogram is achieved, with this reference chromatogram being provided externally.

[0249] The system can be configured to perform the fitting by iterating the fitting, and the system can be configured to perform the iteration at least partially until the number of detectable peaks or detectable compounds in a obtained chromatogram is maximized, and at least partially by comparing the peaks in a obtained chromatogram with the peaks in the reference chromatogram until maximum agreement with the reference chromatogram is achieved.

[0250] The system can be configured to perform the fitting by iterating the fitting, and the system can be configured to perform the iteration at least partially until the number of detectable peaks or detectable compounds in a obtained chromatogram is maximized, and at least partially by comparing the peaks in a obtained chromatogram with the peaks in a reference chromatogram until maximum agreement with the reference chromatogram is achieved, with this reference chromatogram being provided externally.

[0251] The system can be configured to use peak threshold detection algorithms when detecting and / or comparing peaks.

[0252] The system can be configured to use peak threshold detection based on peak height or signal height.

[0253] The system can be configured to use peak threshold detection based on the peak area or signal area.

[0254] The system can be configured to use peak threshold detection based on the peak detection algorithms used in the coding sequence.

[0255] The system can be configured to use peak threshold detection algorithms based on machine learning techniques.

[0256] The system can be configured to perform the optimization procedure at least partially using a manual optimization procedure.

[0257] The system can be configured to perform the step of acquiring a reference chromatogram before the step of at least partially using the manual optimization procedure.

[0258] The system can be configured to allow a manual optimization procedure that includes the following: Manual definition of a detection window by a user, where the detection window encompasses a time from the start of the detection to the end of the detection, Manual definition by the user of a first and a last eluted compound to be present in an optimized chromatogram, where the optimized chromatogram comprises a chromatogram obtained at the end of the optimization procedure.

[0259] The system can be configured to allow the user to define the detection window by manually cutting out a section of interest from a received chromatogram. where the defined detection window is based on the section of interest in the obtained chromatogram, and where the cropping is performed on a dedicated user interface.

[0260] The system can be configured to allow the user to use a mass spectrometer and / or a diode array detector and / or another peak detection instrument to define the first and last eluted compounds present in the optimized chromatogram.

[0261] The system can be configured to allow manual adjustment of the time difference t in the manual optimization procedure. Verz and the time difference t Verz 'to enable the user, and The controller can be configured to automatically optimize the rest of a workflow.

[0262] The system can be configured to allow manual adjustment of the time difference t in the manual optimization procedure. Verz and the time difference t Verz' to enable by the user, and can be configured so that the user can manually adjust the rest of a workflow.

[0263] The flow from the first separation column to the detector in the first configuration (I) can have a flow rate in the range of 0 to 10 ml / min, preferably 0 to 100 µl / min, such as 0.1 to 10 µl / min.

[0264] The flow from the second separation column to disposal can have a flow rate in the range of 0 to 10 ml / min, preferably 0 to 100 µl / min, such as 0.1 to 10 µl / min.

[0265] In the first configuration (I), the pressure provided by the separation pump can be in the range of 100 bar to 2,000 bar, preferably 200 bar to 1,500 bar, for example 500 bar to 1,500 bar.

[0266] The controller can be configured to control the system to perform the procedure described above.

[0267] The system can be designed to execute the procedure described above.

[0268] The system can be designed to perform any step of the procedure described above.

[0269] The system can be configured to optimize solvent supply.

[0270] Optimizing solvent supply can include optimizing a solvent composition at the start of a gradient supply.

[0271] Optimizing solvent supply can involve optimizing a solvent composition at the end of a gradient supply.

[0272] Optimizing the solvent supply can include optimizing the slope of a gradient supply.

[0273] In another aspect, the present invention relates to a use of the liquid chromatography system for tandem liquid chromatography.

[0274] The use may consist of carrying out the procedure as set out in one of the preceding procedure implementation forms.

[0275] The pre-column switching valve can be used to switch the liquid chromatography system to the first switching time T. II to switch from the first configuration to the second configuration.

[0276] The post-column switching valve can be used to switch the liquid chromatography system to the second switching time T. III to switch from the second configuration to the third configuration.

[0277] The pre-column switching valve can be used to switch the liquid chromatography system to the third switching time T. IV to switch from the third configuration to the fourth configuration.

[0278] The post-column switching valve can be used to switch the liquid chromatography system to the fourth switching time T. Ito switch from the fourth configuration to the first configuration.

[0279] The control system can be used to automatically execute a workflow according to embodiments of the present invention.

[0280] In another aspect, the present invention relates to a computer program product comprising instructions which, when executed by a processor, cause the processor to control a liquid chromatography system to carry out the method according to embodiments of the present invention.

[0281] In another aspect, the present invention relates to a computer-readable medium comprising instructions which, when executed by a processor, cause the processor to control a liquid chromatography system to carry out the method according to embodiments of the present invention.

[0282] In another aspect, the present invention relates to a data carrier signal that transmits the computer program product according to an embodiment of the present invention.

[0283] The present technology is also described by the following numbered embodiments.

[0284] The following refers to process embodiments. These embodiments are abbreviated with the letter "M" followed by a number. Whenever this document refers to "process embodiments," these embodiments are meant. M1. A process carried out in a liquid chromatography system, the process comprising: in a first configuration (I), wherein a first separation column is fluidically connected to a separation pump and a detector, guiding a flow from the first separation column to the detector by means of the separation pump in the first configuration (I), and Switching the liquid chromatography system from the first configuration (I) to a second configuration (II), wherein the first separation column is fluidically connected to a second pump and the detector, and directing a flow from the first separation column to the detector by means of the second pump in the second configuration (II). M2. The method according to the preceding embodiment, wherein in the first configuration (I) a second separation column is fluidically connected to the second pump and a disposal, and wherein the method in the first configuration (I) further comprises directing a flow from the second separation column to the disposal by means of the second pump. M3. The method according to one of the preceding embodiments with the features of embodiment M2, wherein in the second configuration (II) the second separation column is fluidically connected to the separation pump and the disposal, wherein the method in the second configuration (II) further comprises directing a flow from the second separation column to the disposal by means of the separation pump. M4. The method according to one of the preceding embodiments, wherein the method comprises switching the liquid chromatography system from the second configuration (II) to a third configuration (III), wherein the first separation column is fluidically connected to the second pump and a disposal, and wherein the method in the third configuration further comprises directing a flow from the first separation column to the disposal by means of the second pump (III). M5. The method according to the preceding embodiment, wherein in the third configuration (III) the second separation column is fluidically connected to the separation pump and the detector, wherein the method in the third configuration (III) further comprises directing a flow from the second separation column to the detector by means of the separation pump. M6. The method according to one of the preceding embodiments, wherein the liquid chromatography system is switched on at a first switching time (T II ) switches from the first configuration (I) to the second configuration (II). M7. The method according to the preceding embodiment and with the features of embodiment M4, wherein the liquid chromatography system at a second switching time (T III ) switches from the second configuration (II) to the third configuration, where the second switching time (T III ) after the first switching time (T II) lies. M8. The method according to the preceding embodiment, where a time difference t Verz between the second switching time (T III ) and the first switching time (T II ) on a volume V5 of the second separation column, on a volume V verb of fluid connections connected to the second separation column and based on a flow rate F of the separation pump. M9. The method according to the preceding embodiment, wherein the time difference t Verz the following equation is satisfied: tVerz=(V5+Vverb) / F. M10. The method according to one of the preceding embodiments with the features of embodiment M7, where the time difference t Verz between 0 minutes and 100 minutes, preferably between 1 minute and 20 minutes, more preferably between 1 minute and 10 minutes. M11. The method according to one of the preceding embodiments with the features of embodiment M6, where at the first switching time (T II ) a flow rate F' of the second pump is essentially equal to the flow rate F of the separation pump. M12. The method according to one of the preceding embodiments with the features of embodiment M4, where the flow rate F' of the second pump in the third configuration (III) is significantly larger than the flow rate F of the separation pump in the third configuration (III). M13. The method according to one of the preceding embodiments with the features of embodiment M4, wherein the method comprises switching the liquid chromatography system from the third configuration (III) to a fourth configuration (IV), wherein the first separation column is fluidically connected to the separation pump and a disposal, and wherein the method in the fourth configuration (IV) further comprises directing a flow from the first separation column to the disposal by means of the separation pump. M14. The method according to the preceding embodiment, wherein in the fourth configuration (IV) the second separation column is fluidically connected to the second pump and the detector, and wherein the method in the fourth configuration (IV) further comprises directing a flow from the second separation column to the detector by means of the second pump. M15. The method according to one of the preceding embodiments with the features of embodiment M13, wherein the liquid chromatography system is switched from the third configuration (III) to a third switching time (T). IV ) switches to the fourth configuration (IV), with the third switching time (T IV ) after the second switching time (T III ) lies. M16. The method according to one of the preceding embodiments with the features of embodiment M13, wherein the liquid chromatography system at a fourth switching time (T I ) is switched from the fourth configuration (IV) back to the first configuration (I), thereby forming a cyclic process and thereby ending a previous cycle and starting a subsequent cycle, where the fourth switching point (T I ) after the third switching point (T IV) lies and where a time difference t Verz ' between the fourth switching point (T I ) and the third switching point (T IV ) on a volume V8' of the first separation column, on a volume V verb ' of fluid connections connected to the first separation column, and based on a flow rate F of the separation pump. M17. The method according to one of the preceding embodiments with the features of embodiment M16, where the time difference t Verz the following equation is satisfied: tVerz'=(V8'+Vverb') / F. M18. The method according to one of the preceding embodiments with the features of embodiment M15, where at the third switching time (T IV ) the flow rate F' of the second pump is essentially equal to the flow rate of the separation pump. M19. The method according to one of the preceding embodiments with the features of embodiment M16, wherein the flow rate F' of the second pump in the first configuration (I) is significantly larger than the flow rate F of the separation pump in the first configuration (I). M20. The method according to one of the preceding embodiments with the features of embodiment M16, where the time difference t Verz between 0 minutes and 100 minutes, preferably between 1 minute and 20 minutes, more preferably between 1 minute and 10 minutes. M21. The method according to one of the preceding embodiments with the features of embodiment M16, where the time difference t Verz ' essentially with the time difference t Verz agrees. M22. The method according to one of the preceding embodiments with the features of embodiment M16, where the volume V8' of the first separation column is essentially the same as the volume V5 of the second separation column. M23. The method according to one of the preceding embodiments with the features of embodiment M16, where the volume V verb ' of the fluid compounds connected with the first separation column essentially with the volume V verb of fluid connections that are connected to the second separation column. M24. The method according to one of the preceding embodiments with the features of embodiment M16, the procedure includes, after the fourth switching time T I , that the liquid chromatography system at a subsequent first switching time T II ' switches back to the second configuration, where the subsequent first switching time T II ' after the fourth switching point T I lies, and where the time difference between the subsequent first switching time T II ' and the fourth switching point T I equal to t Verz is. M25. The method according to one of the preceding embodiments with the features of embodiment M24, where the subsequent cycle follows the same temporal sequence, so that the times T II ', T III ', T IV ', T I ' of the following cycle at the respective time points T II , T III , T IV , T I correspond to the previous cycle. M26. The method according to one of the preceding embodiments, wherein the method comprises switching the liquid chromatography system from the first configuration (I) to the second configuration (II) by means of a controller. M27. The method according to the preceding embodiment and with the features of embodiment M4, wherein the method includes switching the liquid chromatography system from the second configuration (II) to the third configuration (III) by means of the control. M28. The method according to one of the preceding embodiments and with the features of embodiments M13 and M26, wherein the method includes switching the liquid chromatography system from the third configuration (III) to the fourth configuration (IV) by means of the control. M29. The method according to one of the preceding embodiments and with the features of embodiments M7 and M26, wherein the method includes switching the liquid chromatography system from the fourth configuration (IV) to the first configuration (I) by means of the control. M30. The method according to one of the preceding embodiments and with the features of embodiments M7, M11 and M26, wherein the method comprises controlling the flow rate F of the first pump and the flow rate F' of the second pump by the controller. M31. The method according to one of the preceding embodiments, wherein the liquid chromatography system includes a pre-column switching valve, wherein the upstream column switching valve comprises a multitude of ports and a multitude of connecting elements for interchangeably connecting the ports, where a connection of the pre-column switching valve to the separation pump is fluidically connected, a connection of the pre-column switching valve to the second pump is fluidically connected, a connection of the pre-column switching valve to the first separation column is fluidically connected, The connection of the pre-column switching valve is fluidically connected to the second separation column. M32. The method according to one of the preceding embodiments with the features of embodiment M31, wherein in the first configuration (I) the port of the pre-column switching valve which is fluidically connected to the separation pump is connected to the port of the pre-column switching valve which is fluidically connected to the first separation column, and wherein in the first configuration (I) the port of the pre-column switching valve which is fluidically connected to the second pump is fluidically connected to the port of the pre-column switching valve which is fluidically connected to the second separation column. M33. The method according to one of the preceding embodiments with the features of embodiment M31, wherein in the second configuration (II) the connection of the pre-column switching valve which is fluidically connected to the separation pump is fluidically connected to the connection of the pre-column switching valve which is fluidically connected to the second separation column, and wherein in the second configuration (II) the connection of the pre-column switching valve which is fluidically connected to the second pump is fluidically connected to the connection of the pre-column switching valve which is fluidically connected to the first separation column. M34. The method according to one of the preceding embodiments with the features of embodiments M6 and M31, wherein the method involves switching the liquid chromatography system via the pre-column switching valve from the first configuration (I) to the second configuration (II) at the first switching time T IIincludes. M35. The method according to one of the preceding embodiments with the features of embodiments M24 and M31, wherein the method involves switching the liquid chromatography system via the pre-column switching valve from the first configuration (I) to the second configuration (II) at the subsequent first switching time T II ' in the following cycle. M36. The method according to one of the preceding embodiments with the features of embodiments M31 and M4, wherein in the third configuration (III) the port of the pre-column switching valve which is fluidically connected to the separation pump is fluidically connected to the port of the pre-column switching valve which is fluidically connected to the second separation column, and wherein in the third configuration (III) the connection of the pre-column switching valve which is fluidically connected to the second pump is fluidically connected to the connection of the pre-column switching valve which in the third configuration (III) is fluidically connected to the first separation column. M37. The method according to one of the preceding embodiments with the features of embodiments M13 and M31, wherein in the fourth configuration (IV) the port of the pre-column switching valve which is fluidically connected to the separation pump is fluidically connected to the port of the pre-column switching valve which is fluidically connected to the first separation column, and wherein in the fourth configuration (IV) the connection of the pre-column switching valve which is fluidically connected to the second pump is fluidically connected to the connection of the pre-column switching valve which is fluidically connected to the second separation column. M38. The method according to one of the preceding embodiments with the features of embodiments M16 and M31, wherein the method involves switching the liquid chromatography system via the pre-column switching valve from the third configuration (III) to the fourth configuration (IV) at the third switching time T IV includes. M39. The method according to one of the preceding embodiments with the features of embodiments M25 and M31, wherein the method involves switching the liquid chromatography system via the pre-column switching valve from the third configuration (III) to the fourth configuration (III) at the subsequent third switching time T IV ' in the following cycle. M40. Method according to one of the preceding embodiments with the features of embodiments M26, M34 and M35, the switching of the liquid chromatography system from the first configuration (I) to the second configuration (II) via the pre-column switching valve is controlled by the controller. M41. Method according to one of the preceding embodiments having the features of embodiments M26, M38 and M39, the switching of the liquid chromatography system from the third configuration (III) to the fourth configuration (IV) via the pre-column switching valve is controlled by the control unit. M42. The method according to one of the preceding embodiments, wherein the liquid chromatography system includes a post-column switching valve, wherein the post-column switching valve comprises a multitude of ports and a multitude of connecting elements for interchangeably connecting the ports, where a connection of the post-column switching valve is fluidically connected to the first separation column, a connection of the post-column switching valve is fluidically connected to the second separation column, a connection of the post-column switching valve is fluidically connected to the disposal system, The post-column switching valve is fluidically connected to the detector. M43. The method according to one of the preceding embodiments with the features of embodiment M42, wherein in the first configuration (I) the port of the post-column switching valve which is fluidically connected to the first separation column is fluidically connected to the port of the post-column switching valve which is fluidically connected to the detector, and wherein in the first configuration (I) the port of the post-column switching valve which is fluidically connected to the second separation column is fluidically connected to the port of the post-column switching valve which is fluidically connected to the disposal. M44. The method according to one of the preceding embodiments with the features of embodiment M42, wherein in the second configuration (II) the port of the post-column switching valve which is fluidically connected to the first separation column is fluidically connected to the port of the post-column switching valve which is fluidically connected to the detector, and wherein in the second configuration (II) the port of the post-column switching valve which is fluidically connected to the second separation column is fluidically connected to the port of the post-column switching valve which is fluidically connected to the disposal. M45. The method according to one of the preceding embodiments with the features of embodiments M4 and M42, wherein in the third configuration (III) the port of the post-column switching valve which is fluidically connected to the first separation column is fluidically connected to the port of the post-column switching valve which is fluidically connected to a disposal, and wherein in the third configuration (III) the port of the post-column switching valve which is fluidically connected to the second separation column is fluidically connected to the port of the post-column switching valve which is fluidically connected to the detector. M46. The method according to one of the preceding embodiments with the features of embodiments M4 and M42, wherein the method involves switching the liquid chromatography system via the post-column switching valve from the second configuration (II) to the third configuration (III) at the second switching time T III includes. M47. The method according to one of the preceding embodiments with the features of embodiments M25 and M42, wherein the method involves switching the liquid chromatography system in the subsequent cycle via the post-column switching valve from the second configuration (II) to the third configuration (III) at the subsequent second switching time T. III ' includes. M48. The method according to one of the preceding embodiments with the features of embodiments M13 and M42, wherein in the fourth configuration (IV) the connection of the post-column switching valve which is fluidically connected to the first separation column, in the fourth configuration (IV) is fluidically connected to the connection of the post-column switching valve which is fluidically connected to a disposal, and wherein in the fourth configuration (IV) the port of the post-column switching valve which is fluidically connected to the second separation column is fluidically connected to the port of the post-column switching valve which is fluidically connected to the detector. M49. The method according to one of the preceding embodiments with the features of embodiments M16 and M42, wherein the method involves switching the liquid chromatography system via the post-column switching valve from the fourth configuration (IV) to the first configuration (I) at the fourth switching time T I includes. M50. The method according to one of the preceding embodiments with the features of embodiments M25 and M42, wherein the method involves switching the liquid chromatography system in the subsequent cycle via the post-column switching valve from the fourth configuration (IV) to the first configuration (I) at the subsequent fourth switching time T I ' includes. M51. Method according to one of the preceding embodiments having the features of embodiments M4, M26 and M42, wherein the switching of the liquid chromatography system via the post-column switching valve from the second configuration (II) to the third configuration (III) is controlled by the control unit. M52. The method according to one of the preceding embodiments with the features of embodiments M13, M26 and M42, the switching of the liquid chromatography system from the fourth configuration (IV) to the first configuration (I) via the post-column switching valve is controlled by the controller. M53. The method according to one of the embodiments of M1 to M41 with the features of embodiments M2, wherein the liquid chromatography system comprises a double-tube electrospray source, and wherein the double-tube electro-spray source comprises a first tube comprising the first separation column and a second tube comprising the second separation column. M54. The method according to the preceding embodiment, wherein an end section of the first tube includes a first emitter, wherein the first emitter is configured to spray into the detector, and wherein an end section of the second tube includes a second emitter, wherein the second emitter is configured to spray into the detector. M55. The method according to the preceding embodiment, wherein the detector comprises a mass spectrometry detector. M56. The method according to one of the two preceding embodiments, wherein in the first configuration (I) the first tube is enabled to spray from the first emitter into the detector by applying a high voltage to the first tube in the first configuration (I). M57. The method according to one of the 3 preceding embodiments, wherein in the second configuration (II) the first tube is enabled to spray from the first emitter into the detector by applying a high voltage to the first tube in the second configuration (II). M58. The method according to one of the 4 embodiments and with the features of embodiment M7, wherein in the third configuration (III) the second tube is enabled to spray from the second emitter into the detector by applying a high voltage to the second tube in the third configuration (III). M59. The method according to one of the 5 preceding embodiments and with the features of embodiment M13, wherein in the fourth configuration (IV) the second tube is enabled to spray from the second emitter into the detector by applying a high voltage to the second tube in the fourth configuration (IV). M60. The method according to one of the 4 preceding embodiments, wherein the high voltage is in a range between 1 kV and 5 kV. M61. The method according to one of the preceding embodiments with the features of embodiments M7, M57 and M58, wherein the method involves switching the liquid chromatography system from the second configuration (II) to the third configuration (III) at the second switching time T III includes by switching from the first tube, which is enabled to spray from the first emitter into the detector, to the second tube, which is enabled to receive from the second emitter into the detector. M62. The method according to one of the preceding embodiments with the features of embodiments M57, M58 and M25, wherein the method involves switching the liquid chromatography system in the subsequent cycle from the second configuration (II) to the third configuration (III) at the subsequent second switching time T III ' includes, by switching from the first tube, which is enabled to spray from the first emitter into the detector, to the second tube, which is enabled to spray from the second emitter into the detector. M63. The method according to one of the preceding embodiments with the features of embodiments M16, M56 and M59, wherein the method involves switching the liquid chromatography system from the fourth configuration (IV) to the first configuration (I) at the fourth switching time (T I ) includes, by switching from the second tube, which is enabled to spray from the second emitter into the detector, to the first tube, which is enabled to spray from the second emitter into the detector. M64. The method according to one of the preceding embodiments with the features of embodiments M56, M59 and M25, wherein the method involves switching the liquid chromatography system in the subsequent cycle from the fourth configuration (IV) to the first configuration (I) at the subsequent fourth switching time T I ' includes, by switching from the second tube, which is enabled to spray from the second emitter into the detector, to the first tube, which is enabled to spray from the second emitter into the detector. M65. The method according to one of the preceding embodiments, wherein the liquid chromatography system includes an injection valve, wherein the injection valve comprises a multitude of ports and a multitude of connecting elements, and whereby one connection of the injection valve is fluidically connected to the second pump, a connection of the injection valve is fluidically connected to a connection of the pre-column switching valve, wherein the method comprises fluidically connecting the port of the injection valve which is fluidically connected to the second pump to the port of the injection valve which is fluidically connected to the pre-column switching valve. M66. The method according to one of the preceding embodiments with the features of embodiment M65, the injection valve further comprises a further multitude of connections, and wherein the method comprises the fluidic connection of the further plurality of ports to a plurality of sample containers which contain a plurality of samples. M67. The method according to one of the preceding embodiments with the features of embodiment M65, wherein the method comprises the injection of a sample from a sample container into the liquid chromatography system via the injection valve. M68. The method according to one of the preceding embodiments with the features of embodiment M67, wherein the method comprises establishing a sample flow from the injection valve to the pre-column switching valve by means of the second pump. M69. The method according to one of the preceding embodiments with the features of embodiment M67, wherein the method comprises switching from injecting a sample from one sample container into the liquid chromatography system via the injection valve to injecting another sample from another sample container into the liquid chromatography system via the injection valve. M70. The method according to one of the preceding embodiments with the features of embodiments M7 and M67, wherein the switching from injecting a sample from one sample container into the liquid chromatography system via the injection valve to injecting another sample from a different sample container into the liquid chromatography system via the injection valve at the first switching time (T II ). M71. The method according to one of the preceding embodiments with the features of embodiments M25 and M67, wherein the switching from injecting a sample from one sample container into the liquid chromatography system via the injection valve to injecting another sample from a different sample container into the liquid chromatography system via the injection valve at the subsequent first switching time (T II ') in the following cycle. M72. The method according to one of the preceding embodiments with the features of embodiments M15 and M67, wherein the switching from injecting a sample from one sample container into the liquid chromatography system via the injection valve to injecting another sample from a different sample container into the liquid chromatography system via the injection valve at the third switching time (T IV ). M73. The method according to one of the preceding embodiments with the features of embodiments M25 and M67, wherein the switching from injecting a sample from one sample container into the liquid chromatography system via the injection valve to injecting another sample from a different sample container into the liquid chromatography system via the injection valve at the subsequent third switching time (T IV ') in the following cycle. M74. The method according to one of the preceding embodiments with the features of embodiment M26, wherein the injection of a sample from a sample container into the liquid chromatography system via the injection valve is controlled by the controller, and the switching from injecting a sample from one sample container into the liquid chromatography system via the injection valve to injecting another sample from another sample container into the liquid chromatography system via the injection valve is controlled by the control unit. M75. Method according to one of the preceding embodiments with the features of embodiments M7, M15 and M16, wherein the method involves starting the provision of a gradient by the separation pump at the first switching time (T II ) includes, wherein the method involves stopping the provision of a gradient by the separation pump at a time T Grad. Stopp includes where time T Grad.Stopp after the second switching time T III lies, and where time T Grad.Stopp before the third switching point T IV lies. M76. The method according to one of the preceding embodiments with the features of embodiment M25, wherein the method involves starting the provision of a gradient by the separation pump at the third switching time (T IV ) includes, wherein the method involves stopping the provision of a gradient by the separation pump at a time T Grad.Stopp includes where time T Grad.Stopp after the fourth switching point T II lies, and where time T Grad.Stopp ' before the subsequent first switching time T II lies in the following cycle. M77. The method according to one of the preceding embodiments with the features of embodiment M26, wherein the method includes controlling the start of the gradient provision and the stop of the gradient provision by the controller. M78. The method according to one of the preceding embodiments with the features of embodiment M6, where at the first switching time (T II ) a solvent composition supplied by the second pump is essentially identical to a solvent composition supplied by the separation pump. M79. The method according to one of the preceding embodiments with the features of embodiment M15, where at the third switching time (T IV ) a solvent composition supplied by the second pump is essentially identical to a solvent composition supplied by the separation pump. M80. The method according to one of the preceding embodiments with the features of embodiments M7 and M16, wherein the method involves starting the detection using a detector at the second switching time (T III ) includes, wherein the method involves stopping the detection by means of the detector at a detector stop time T Det. Stopp includes where the detector stop time T Det. Stopp after the third switching point T IV lies, where the detector stop time T Det. Stopp before the fourth switching point T I lies. M81. The method according to one of the preceding embodiments with the features of embodiment M25, wherein the method involves starting the detection using the detector at the fourth switching time T I includes wherein the method involves stopping the detection by means of the detector at a further detector stop time T Det. Stopp ' includes, where the time of further detector stop times T Det. Stopp ' after the subsequent first switching time T II ' in the following cycle, where the further detector stop time T Det. Stopp' before the subsequent second switching point T III ' lies in the following cycle. M82. The method according to one of the preceding embodiments with the features of embodiment M26, the procedure includes controlling the start of the detection and the stopping of the detection can be controlled by the controller. M83. The method according to one of the preceding embodiments, the procedure involves the use of an optimization procedure to optimize the time difference t Verz and / or the time difference t Verz ' includes. M84. The method according to one of the preceding embodiments with the features of embodiments M26 and M83, the procedure includes at least partially controlling the steps contained in the optimization procedure. M85. The method according to one of the preceding embodiments with the features of embodiment M83, the procedure includes, at least in part, the use of a user interface in the steps of the optimization procedure. M86. The method according to one of the preceding embodiments with the features of embodiment M83, the procedure includes the acquisition of a reference chromatogram. M87. The method according to one of the preceding embodiments with the features of embodiment M83, wherein the method comprises the acquisition of a reference chromatogram containing at least some of the characteristic chromatographic peaks of a sample. M88. The method according to one of the preceding embodiments with the features of embodiment M83, the method includes capturing the reference by performing a linear gradient elution followed by an isocratic phase. M89. The method according to one of the preceding embodiments with the features of embodiment M83, where the optimization procedure includes the execution of an automatic optimization procedure. M90. The method according to one of the preceding embodiments with the features of embodiments M86 and M89, where the step of acquiring a reference chromatogram precedes the step of executing the automatic optimization procedure. M91. The method according to one of the preceding embodiments with the features of embodiment M90, where the automatic optimization procedure adjusts the time difference t Verz and adjusting the time difference t Verz ' includes. M92. The method according to one of the preceding embodiments with the features of embodiment M91, wherein the procedure includes performing the adjustment by iterating the adjustment, and the iteration is performed until the number of detectable peaks or detectable compounds in a obtained chromatogram is maximized. M93. The method according to one of the preceding embodiments with the features of embodiment M91, wherein the method comprises comparing the number of detectable peaks or detectable compounds in the obtained chromatogram with the number of detectable peaks or detectable compounds in the reference chromatogram. M94. The method according to one of the preceding embodiments with the features of embodiment M85, wherein the method comprises comparing the number of detectable peaks or detectable compounds in a obtained chromatogram with the number of detectable peaks or detectable compounds in a reference chromatogram, where this reference chromatogram is provided externally. M95. Method according to one of the preceding embodiments with the features of embodiments M92, M93 and M94, where the detectable peaks or compounds correspond to peptides, proteins and / or other biomolecules. M96. The method according to one of the preceding embodiments with the features of embodiment M91, wherein the procedure includes performing the adjustment by iterating the adjustment, and the iteration is performed by comparing the peaks in a obtained chromatogram with the peaks in the reference chromatogram until maximum agreement with the reference chromatogram is achieved. M97. The method according to one of the preceding embodiments with the features of embodiment M91, wherein the procedure includes performing the adjustment by iterating the adjustment, and wherein the iteration is performed by comparing the peaks in a obtained chromatogram with the peaks in the reference chromatogram until maximum agreement with the reference chromatogram is achieved, and where this reference chromatogram is provided externally. M98. The method according to one of the preceding embodiments with the features of embodiment M91, wherein the procedure includes performing the adjustment by iterating the adjustment, and wherein the iteration is carried out at least partially until the number of detectable peaks or detectable compounds in a obtained chromatogram is maximized, and at least partially by comparing the peaks in a obtained chromatogram with the peaks in the reference chromatogram until maximum agreement with the reference chromatogram is achieved. M99. The method according to one of the preceding embodiments with the features of embodiment M91, wherein the procedure includes performing the adjustment by iterating the adjustment, and wherein the iteration is performed at least partially until the number of detectable peaks or detectable compounds in a obtained chromatogram is maximized, and at least partially by comparing the peaks in a obtained chromatogram with the peaks in a reference chromatogram until maximum agreement with that reference chromatogram is achieved, and where this reference chromatogram is provided externally. M100. The method according to one of the preceding embodiments with the features of one of the embodiments M92 to M99, the method includes the use of peak threshold detection algorithms for the detection and / or comparison of peaks. M101. The method according to one of the preceding embodiments with the features of embodiment M100, the method includes the use of peak threshold detection based on the peak height or signal height. M102. The method according to one of the preceding embodiments with the features of embodiment M100, the method includes the use of peak threshold detection based on the peak area or signal area. M103. The method according to one of the preceding embodiments with the features of embodiment M100, the method includes the use of peak threshold detection based on peak detection algorithms used in the coding sequence. M104. The method according to one of the preceding embodiments with the features of embodiment M100, the method involves the use of peak threshold detection algorithms, which include machine learning techniques. M105. The method according to one of the preceding embodiments with the features of embodiment M86, where the optimization procedure includes at least partially the use of a manual optimization procedure. M106. The method according to one of the preceding embodiments with the features of embodiment M105, where the step of acquiring a reference chromatogram precedes the step of at least partially using the manual optimization procedure. M107. The method according to one of the preceding embodiments with the features of embodiment M105, the manual optimization procedure includes: Manual definition of a detection window by a user, where the detection window encompasses a time from the start of the detection to the end of the detection, Manual definition by the user of a first and a last eluted compound to be present in an optimized chromatogram, where the optimized chromatogram comprises a chromatogram obtained at the end of the optimization procedure. M108. The method according to one of the preceding embodiments with the features of embodiment M107, where the user's definition of the detection window includes manually cutting out a section of interest from a obtained chromatogram, where the defined detection window is based on the section of interest in the obtained chromatogram, and where the cropping is performed on a dedicated user interface. M109. The method according to one of the preceding embodiments with the features of embodiment M107, wherein a mass spectrometer and / or a diode array detector and / or another peak detection instrument is used to determine the first and last eluted compound present in the user's optimized chromatogram. M110. The method according to one of the preceding embodiments with the features of embodiment M107, where the manual optimization procedure involves manually adjusting the time difference t Verz and the time difference t Verz ' encompasses the user, and the control system automatically optimizes the rest of the workflow. M111. The method according to one of the preceding embodiments with the features of embodiment M107, where the manual optimization procedure involves manually adjusting the time difference t Verz and the time difference t Verz ' encompasses the user, and where the user manually adjusts the rest of the workflow. M112. The method according to one of the preceding embodiments, wherein the flow from the first separation column to the detector in the first configuration (I) has a flow rate in the range of 0 to 10 ml / min, preferably 0 to 100 µl / min, such as 0.1 to 10 µl / min. M113. The method according to one of the preceding embodiments with the features of embodiment M2, wherein the flow from the second separation column to disposal has a flow rate in the range of 0 to 10 ml / min, preferably 0 to 100 µl / min, such as 0.1 to 10 µl / min. M114. The method according to one of the preceding embodiments, wherein in the first configuration (I) a pressure provided by the separation pump is in the range of 100 bar to 2,000 bar, preferably 200 bar to 1,500 bar, such as 500 bar to 1,500 bar. M115. The method according to one of the preceding embodiments, wherein the method comprises optimizing a solvent supply. M116. The method according to the preceding embodiment, wherein optimizing the solvent supply comprises optimizing a solvent composition at the start of a gradient supply. M117. The method according to one of the two preceding embodiments, wherein the optimizing of the solvent supply comprises optimizing a solvent composition at the end of a gradient supply. M118. The method according to one of the 3 preceding embodiments, wherein optimizing the solvent supply includes optimizing a gradient supply slope. The following refers to system implementations. These implementations are abbreviated with the letter "S" followed by a number. Whenever "system implementations" are referred to in this document, these implementations are meant. S1. A liquid chromatography system, wherein the system comprises: a first separation column, a separation pump, and a detector wherein the first separation column is configured to be fluidically connected to the separation pump and the detector in a first configuration (I), wherein the system is configured to direct a flow from the first separation column to the detector by means of the separation pump in the first configuration (I), and where the system is configured to switch from the first configuration (I) to a second configuration (II), wherein the first separation column is configured to be fluidically connected to the second pump and detector in the second configuration (II), and the system is configured to direct a flow from the first separation column to the detector in the second configuration (II) using the second pump. S2. The system according to the previous system implementation form, the system further includes: a second separating column, and a disposal, wherein the second separation column is configured to be fluidically connected to the second pump and to the disposal in the first configuration (I), the system is configured to direct a flow from the second separation column to disposal using the second pump in the first configuration (I). S3. The system according to the previous system implementation form, wherein the second separation column is configured to be fluidically connected to the separation pump and to the disposal in the second configuration (II), wherein the system is configured to direct a flow from the second separation column to the disposal by means of the separation pump in the second configuration (II). S4. The system according to one of the preceding system implementation forms, wherein the system is configured to switch from the second configuration (II) to a third configuration (III), wherein the first separation column is configured to be fluidically connected to the second pump and a disposal, and wherein the system is configured to direct a flow from the first separation column to the disposal in the third configuration (III) by means of the second pump. S5. The system according to the previous system implementation form, wherein in the third configuration (III) the second separation column is configured to be fluidically connected to the separation pump and the detector, wherein the system in the third configuration (III) is further configured to direct a flow from the second separation column to the detector by means of the separation pump. S6. The system according to one of the preceding system implementation forms, where the system is configured to start the system at a first switching time (T II ) to switch from the first configuration (I) to the second configuration (II). S7. The system according to one of the preceding system embodiments with the features of embodiment S4, where the system is configured to switch to a second switching time (T III ) to switch from the second configuration (II) to the third configuration, where the second switching time (T III ) after the first switching time (TII ) lies. S8. The system according to the preceding system implementation form, wherein a time difference t Verz between the second switching time (T III ) and the first switching time (T II ) on a volume V5 of the second separation column, on a volume V verb of fluid connections connected to the second separation column and based on a flow rate F of the separation pump. S9. The system according to the preceding system implementation form, where the time difference t Verz the following equation is satisfied: tVerz=(V5+Vverb) / F. S10. The system according to one of the preceding system embodiments with the features of embodiment S7, where the time difference t Verz between 0 minutes and 100 minutes, preferably between 1 minute and 20 minutes, more preferably between 1 minute and 10 minutes. S11. The system according to one of the preceding system embodiments with the features of embodiment S6, where at the first switching time (T II ) a flow rate F' of the second pump is essentially equal to the flow rate F of the separation pump. S12. The system according to one of the preceding system embodiments with the features of embodiment S4, where the flow rate F' of the second pump in the third configuration (III) is significantly larger than the flow rate F of the separation pump in the third configuration (III). S13. System according to one of the preceding system embodiments with the features of embodiment S4, wherein the system is configured to switch from the third configuration (III) to a fourth configuration (IV), wherein the first separation column is fluidically connected to the separation pump and a disposal, and wherein the system is configured to direct a flow from the first separation column to the disposal in the fourth configuration (IV) by means of the separation pump. S14. The system according to the previous system implementation form, wherein in the fourth configuration (IV) the second separation column is fluidically connected to the second pump and the detector and wherein the system is configured to direct a flow from the second separation column to the detector in the fourth configuration (IV) by means of the second pump. S15. The system according to one of the preceding system embodiments with the features of embodiment S13, where the system is configured to disconnect the system from the third configuration (III) at a third switching time (T IV ) to switch to the fourth configuration (IV), where the third switching time (T IV ) after the second switching time (T III ) lies. S16. The system according to one of the preceding system embodiments with the features of embodiment S13, where the system is configured to switch to a fourth switching time (T I ) to switch from the fourth configuration (IV) back to the first configuration (I), thereby forming a cyclic process and thereby ending a previous cycle and starting a subsequent cycle, where the fourth switching point (T I ) after the third switching point (T IV ) lies and where a time difference t Verz ' between the fourth switching point (T I) and the third switching point (T IV ) on a volume V8' of the first separation column, on a volume V verb ' of fluid connections connected to the first separation column, and based on a flow rate F of the separation pump. S17. The system according to the previous system implementation form, where the time difference t Verz the following equation is satisfied: tVerz'=(V8'+Vverb') / F. S18. The system according to one of the preceding system embodiments with the features of embodiment S15, where at the third switching time (T IV ) the flow rate F' of the second pump is essentially equal to the flow rate of the separation pump. S19. The system according to one of the preceding system embodiments with the features of embodiment S16, where the flow rate F' of the second pump in the first configuration (I) is considerably larger than the flow rate F of the separation pump in the first configuration (I). S20. The system according to one of the preceding system embodiments with the features of embodiment S16, where the time difference t Verz between 0 minutes and 100 minutes, preferably between 1 minute and 20 minutes, more preferably between 1 minute and 10 minutes. S21. The system according to one of the preceding system embodiments with the features of embodiment S16, where the time difference t Verz ' essentially with the time difference t Verz agrees. S22. The system according to one of the preceding system embodiments with the features of embodiment S16, where the volume V8' of the first separation column is essentially the same as the volume V5 of the second separation column. S23. The system according to one of the preceding system embodiments with the features of embodiment S16, where the volume V verb ' of the fluid compounds connected with the first separation column essentially with the volume V verb of fluid connections that are connected to the second separation column. S24. The system according to one of the preceding system embodiments with the features of embodiment S16, where the system after the fourth switching time T I is configured to start the system at a subsequent first switching time T II ' to switch back to the second configuration, where the subsequent first switching time T II ' after the fourth switching point T I lies, and where the time difference between the subsequent first switching time T II ' and the fourth switching point T I equal to t Verz is. S25. The system according to the previous system implementation form, where the subsequent cycle follows the same temporal sequence, so that the times T II ', T III ', T IV ', T I ' of the following cycle at the respective time points T II , T III , T IV , T I correspond to the previous cycle. S26. The system according to one of the preceding system implementation forms, The system includes a controller, the system is configured to switch from the first configuration (I) to the second configuration (II) using the controller. S27. The system according to one of the preceding system embodiments with the features of embodiment S4, the system is configured to switch from the second configuration (II) to the third configuration (III) using the controller. S28. The system according to one of the preceding system embodiments with the features of embodiments S13 and S26, the system is configured to switch from the third configuration (III) to the fourth configuration (IV) using the controller. S29. The system according to one of the preceding system embodiments with the features of embodiments S13 and S26, wherein the system is configured to switch the system from the fourth configuration (IV) to the first configuration (I) by means of the controller. S30. The system according to one of the preceding system embodiments with the features of embodiments S7, S11 and S26, the system is configured to control the flow rate F of the first pump and the flow rate F' of the second pump through the controller. S31. The system according to one of the preceding system implementation forms, wherein the liquid chromatography system includes a pre-column switching valve, wherein the upstream column switching valve comprises a multitude of ports and a multitude of connecting elements for interchangeably connecting the ports, where a connection of the pre-column switching valve to the separation pump is fluidically connected, a connection of the pre-column switching valve to the second pump is fluidically connected, a connection of the pre-column switching valve to the first separation column is fluidically connected, The connection of the pre-column switching valve is fluidically connected to the second separation column. S32. The system according to the previous system implementation form, wherein in the first configuration (I) the port of the pre-column switching valve which is fluidically connected to the separation pump is connected to the port of the pre-column switching valve which is fluidically connected to the first separation column, and wherein in the first configuration (I) the port of the pre-column switching valve which is fluidically connected to the second pump is fluidically connected to the port of the pre-column switching valve which is fluidically connected to the second separation column. S33. The system according to one of the preceding system embodiments with the features of embodiment S31, wherein in the second configuration (II) the port of the pre-column switching valve which is fluidically connected to the separation pump is fluidically connected to the port of the pre-column switching valve which is fluidically connected to the second separation column, and wherein in the second configuration (II) the connection of the pre-column switching valve which is fluidically connected to the second pump is fluidically connected to the connection of the pre-column switching valve which is fluidically connected to the first separation column. S34. The system according to one of the preceding system embodiments with the features of embodiments S6 and S31, the system is configured to switch the system via the pre-column switching valve at the first switching time T II to switch from the first configuration (I) to the second configuration (II). S35. The system according to one of the preceding system embodiments with the features of embodiments S24 and S31, where the system is configured to operate at the subsequent first switching time T II ' to switch from the first configuration (I) to the second configuration (II) via the pre-column switching valve in the subsequent cycle. S36. The system according to one of the preceding system embodiments with the features of embodiments S24 and S4, wherein in the third configuration (III) the port of the pre-column switching valve which is fluidically connected to the separation pump is fluidically connected to the port of the pre-column switching valve which is fluidically connected to the second separation column, and wherein in the third configuration (III) the connection of the pre-column switching valve which is fluidically connected to the second pump is fluidically connected to the connection of the pre-column switching valve which in the third configuration (III) is fluidically connected to the first separation column. S37. The system according to one of the preceding system embodiments with the features of embodiments S13 and S31, wherein in the fourth configuration (IV) the port of the pre-column switching valve which is fluidically connected to the separation pump is fluidically connected to the port of the pre-column switching valve which is fluidically connected to the first separation column, and wherein in the fourth configuration (IV) the connection of the pre-column switching valve which is fluidically connected to the second pump is fluidically connected to the connection of the pre-column switching valve which is fluidically connected to the second separation column. S38. The system according to one of the preceding system embodiments with the features of embodiments S16 and S31, the system is configured to switch via the upstream column switching valve at the third switching time T IV to switch from the third configuration (III) to the fourth configuration (IV). S39. The system according to one of the preceding system embodiments with the features of embodiments S25 and S31, the system is configured to switch via the upstream column switching valve in the subsequent cycle to the subsequent third switching time T IV ' to switch from the third configuration (III) to the fourth configuration (III). S40. The system according to one of the preceding system embodiments with the features of embodiments S26, S34 and S35, the system is configured to control the switching from the first configuration (I) to the second configuration (II) via the upstream column switching valve by the controller. S41. The system according to one of the preceding system embodiments with the features of embodiments S26, S38 and S39, the system is configured to control the switching of the system via the upstream column switching valve from the third configuration (III) to the fourth configuration (IV) by the controller. S42. The system according to one of the preceding system implementation forms, the system includes a post-column switching valve, wherein the post-column switching valve comprises a multitude of ports and a multitude of connecting elements for interchangeably connecting the ports, where a connection of the post-column switching valve is fluidically connected to the first separation column, a connection of the post-column switching valve is fluidically connected to the second separation column, a connection of the post-column switching valve is fluidically connected to the disposal system, The post-column switching valve is fluidically connected to the detector. S43. The system according to the previous system implementation form, wherein in the first configuration (I) the port of the post-column switching valve which is fluidically connected to the first separation column is fluidically connected to the port of the post-column switching valve which is fluidically connected to the detector, and wherein in the first configuration (I) the port of the post-column switching valve which is fluidically connected to the second separation column is fluidically connected to the port of the post-column switching valve which is fluidically connected to the disposal. S44. The system according to one of the preceding system embodiments with the features of embodiment S42, wherein in the second configuration (II) the port of the post-column switching valve which is fluidically connected to the first separation column is fluidically connected to the port of the post-column switching valve which is fluidically connected to the detector, and wherein in the second configuration (II) the port of the post-column switching valve which is fluidically connected to the second separation column is fluidically connected to the port of the post-column switching valve which is fluidically connected to the disposal. S45. The system according to one of the preceding system embodiments with the features of embodiments S4 and S42, wherein in the third configuration (III) the port of the post-column switching valve which is fluidically connected to the first separation column is fluidically connected to the port of the post-column switching valve which is fluidically connected to a disposal, and wherein in the third configuration (III) the port of the post-column switching valve which is fluidically connected to the second separation column is fluidically connected to the port of the post-column switching valve which is fluidically connected to the detector. S46. The system according to one of the preceding system embodiments with the features of embodiments S4 and S42, the system is configured to switch at the second switching time T III to switch from the second configuration (II) to the third configuration (III) via the post-column switching valve. S47. The system according to one of the preceding system embodiments with the features of embodiments S25 and S42, where the system is configured to switch at the subsequent second switching time T III ' to switch from the second configuration (II) to the third configuration (III) via the post-column switching valve in the subsequent cycle. S48. The system according to one of the preceding system embodiments with the features of embodiments S13 and S42, wherein in the fourth configuration (IV) the connection of the post-column switching valve which is fluidically connected to the first separation column, in the fourth configuration (IV) is fluidically connected to the connection of the post-column switching valve which is fluidically connected to a disposal, and wherein in the fourth configuration (IV) the port of the post-column switching valve which is fluidically connected to the second separation column is fluidically connected to the port of the post-column switching valve which is fluidically connected to the detector. S49. The system according to one of the preceding embodiments with the features of embodiments S17 and S42, the system is configured to switch the system via the post-column switching valve to the fourth switching time T I to switch from the fourth configuration (IV) to the first configuration (I). S50. The system according to one of the preceding embodiments with the features of embodiments S25 and S42, the system is configured to switch at the subsequent fourth switching time T I ' to switch from the fourth configuration (IV) to the first configuration (I) via the post-column switching valve in the subsequent cycle. S51. The system according to one of the preceding embodiments with the features of embodiments S4, S26 and S42, the system is configured to switch from the second configuration (II) to the third configuration (III) via the post-column switching valve, controlled by the controller. S52. System according to one of the preceding embodiments with the features of embodiments S13, S26 and S42, the system is configured to control the switching from the fourth configuration (IV) to the first configuration (I) via the post-column switching valve by the controller. S53. The system according to one of the system implementation forms from S1 to S41 with the features of embodiment S2, the system includes a double-pipe electro-spray source and wherein the double-tube electro-spray source comprises a first tube comprising the first separation column and a second tube comprising the second separation column. S54. The system according to the previous system implementation form, wherein an end section of the first tube includes a first emitter, wherein the first emitter is configured to spray into the detector, and wherein an end section of the second tube includes a second emitter, wherein the second emitter is configured to spray into the detector. S55. The system according to one of the two preceding system implementation forms, the detector includes a mass spectrometry detector. S56. The system according to one of the 3 preceding system implementation forms, wherein the system is configured to enable the first tube to spray from the first emitter into the detector in the first configuration (I) by applying a high voltage to the first tube in the first configuration (I). S57. The system according to one of the preceding system embodiments with the features of embodiments S54 and S55, wherein the system is configured to enable the first tube to spray from the first emitter into the detector in the second configuration (II) by applying a high voltage to the first tube in the second configuration (II). S58. The system according to one of the preceding system embodiments with the features of embodiments S7, S54 and S55, wherein the system is configured to enable the second tube to spray from the second emitter into the detector in the third configuration (III) by applying a high voltage to the second tube in the third configuration (III). S59. The system according to one of the preceding system embodiments with the features of embodiments S13, S54 and S55, wherein the system is configured to enable the second tube to spray from the second emitter into the detector in the fourth configuration (IV) by applying a high voltage to the second tube in the fourth configuration (IV). S60. The system according to the 4 preceding system configurations, wherein the high voltage is in a range between 1 kV and 5 kV. S61. The system according to one of the preceding system embodiments with the features of embodiments S57 and S58, the system is configured to switch at the second switching time T III to switch from the second configuration (II) to the third configuration (III), by switching the first tube, which is enabled to spray from the first emitter into the detector, to the second tube, which is enabled to spray from the second emitter into the detector. S62. The system according to one of the preceding system embodiments with the features of embodiments S57, S58 and S25, where the system is configured to switch to the subsequent second switching time T in the following cycle. III ' to switch from the second configuration (II) to the third configuration (III), by switching the first tube, which is enabled to spray from the first emitter into the detector, to the second tube, which is enabled to spray from the second emitter into the detector. S63. The system according to one of the preceding system embodiments with the features of embodiments S56 and S59, the system is configured to switch at the fourth switching time (T I ) to switch from the fourth configuration (IV) to the first configuration (I), by switching from the second tube, which is enabled to spray from the second emitter into the detector, to the first tube, which is enabled to spray from the first emitter into the detector. S64. The system according to one of the preceding system embodiments with the features of embodiments S56, S59 and S25, where the system is configured to switch to the subsequent fourth switching time T in the following cycle I ' to switch from the fourth configuration (IV) to the first configuration (I), by switching from the second tube, which is enabled to spray from the second emitter into the detector, to the first tube, which is enabled to spray from the first emitter into the detector. S65. The system according to one of the preceding system implementation forms, the system includes an injection valve, wherein the injection valve comprises a multitude of ports and a multitude of connecting elements, and whereby one connection of the injection valve is fluidically connected to the second pump, a connection of the injection valve is fluidically connected to a connection of the pre-column switching valve, where the system is configured to fluidic connection of the injection valve port, which is fluidically connected to the second pump, to the injection valve port, which is fluidically connected to the pre-column switching valve. S66. The system according to the preceding system embodiment, wherein the injection valve further comprises a further plurality of ports, and the system can be configured to fluidically connect the other multitude of ports to a multitude of sample containers containing a multitude of samples. S67. The system according to one of the preceding system embodiments with the features of embodiment S65, the system is configured to inject a sample from a sample container into the liquid chromatography system via the injection valve. S68. The system according to one of the preceding system embodiments with the features of embodiment S67, the system is configured to generate a sample flow from the injection valve to the pre-column switching valve using the second pump. S69. The system according to one of the preceding system embodiments with the features of embodiment S67, the system is configured to switch from injecting one sample from one sample container into the system via the injection valve to injecting another sample from a different sample container into the system via the injection valve. S70. The system according to one of the preceding system embodiments with the features of embodiments S7 and S67, wherein the switching from injecting a sample from one sample container into the system via the injection valve to injecting another sample from a different sample container into the liquid chromatography system via the injection valve at the first switching time (T II ). S71. The system according to one of the preceding system embodiments with the features of embodiments S25 and S67, wherein the switching from injecting a sample from one sample container into the system by means of the injection valve to injecting another sample from another sample container into the liquid chromatography system by means of the injection valve at the subsequent first switching time (T II ') in the following cycle. S72. The system according to one of the preceding system embodiments with the features of embodiments S4 and S67, wherein the switching from injecting a sample from one sample container into the system via the injection valve to injecting another sample from a different sample container into the liquid chromatography system via the injection valve at the third switching time (T IV ). S73. The system according to one of the preceding system embodiments with the features of embodiments S25 and S67, wherein the switching from injecting a sample from one sample container into the system via the injection valve to injecting another sample from a different sample container into the liquid chromatography system via the injection valve at the subsequent third switching time (T IV ') in the following cycle. S74. The system according to one of the preceding system embodiments with the features of embodiments S26, the system is configured to control the injection of a sample from a sample container into the system via the injection valve through the controller and the system is configured to control the switching from injecting one sample from one sample container into the system via the injection valve to injecting another sample from a different sample container into the system via the injection valve. S75. The system according to one of the preceding system embodiments with the features of embodiments S7, S15 and S16, wherein the system is configured to switch at the first switching time (T II ) to start the provision of a gradient by the separation pump, the system is configured to provide a gradient through the separation pump at a time T Grad. Stopp to stop where time T Grad.Stopp after the second switching time T III lies, and where time T Grad.Stopp before the third switching point T IV lies. S76. The system according to one of the preceding system embodiments with the features of embodiment S25, the system is configured to switch at the third switching time (T IV ) to start the provision of a gradient by the separation pump, the system is configured to provide a gradient through the separation pump at a time T Grad. Stopp ' to stop, where time T Grad.Stopp after the fourth switching point T II lies, and where time T Grad.Stopp ' before the subsequent first switching time T II ' lies in the following cycle. S77. The system according to one of the preceding system embodiments with the features of embodiment S26, the system is configured to control the start and stop of gradient provisioning by the controller. S78. The system according to one of the preceding system embodiments with the features of embodiment S6, where at the first switching time (T II ) a solvent composition supplied by the second pump is essentially identical to a solvent composition supplied by the separation pump. S79. The system according to one of the preceding system embodiments with the features of embodiment S15, wherein at the third switching time (T IV ) a solvent composition supplied by the second pump is essentially identical to a solvent composition supplied by the separation pump. S80. The system according to one of the preceding system embodiments with the features of embodiments S7 and S16, the system is configured to detect using a detector at the second switching time (T III ) to start, where the system is configured to detect using the detector at a detector stop time T Det. Stopp to stop where the detector stop time T Det. Stopp after the third switching point T IV lies, where the detector stop time T Det. Stopp before the fourth switching point T I lies. S81. The system according to one of the preceding system embodiments with the features of embodiment S25, the system is configured to detect using the detector at the fourth switching time T I to start, where the system is configured to detect using the detector at a further detector stop time T Det. Stopp ' to stop, where the time of further detector stop times T Det. Stopp ' after the subsequent first switching time T II ' in the following cycle, where the further detector stopping time T Det. Stopp ' before the subsequent second switching point T III ' lies in the following cycle. S82. The system according to one of the preceding system embodiments with the features of embodiment S26, the system is configured to control the start of detection and to be able to control the stop of detection by the controller. S83. The system according to one of the preceding system execution modes, wherein the system is configured to use an optimization procedure to determine the time difference t Verz and / or the time difference t Verz ' to optimize. S84. The system according to one of the preceding system embodiments with the features of embodiments S26 and S83, where the system is configured to at least partially control the steps included in the optimization procedure. S85. The system according to one of the preceding system implementation forms, wherein the system includes a user interface. S86. The system according to one of the preceding system embodiments with the features of embodiments S83 and S85, where the system is configured to use the user interface at least partially in the steps of the optimization procedure. S87. The system according to one of the preceding system embodiments with the features of embodiment S83, the system is configured to acquire a reference chromatogram. S88. The system according to one of the preceding system embodiments with the features of embodiment S83, the system is configured to acquire a reference chromatogram that contains at least some of the characteristic chromatographic peaks of a sample. S89. The system according to one of the preceding system embodiments with the features of embodiment S83, the system is configured to acquire the reference by performing a linear gradient elution followed by an isocratic phase. S90. The system according to one of the preceding system embodiments with the features of embodiment S83, wherein the optimization procedure comprises the execution of an automatic optimization procedure, where the system is configured to run the automatic optimization procedure. S91. The system according to one of the preceding system embodiments with the features of embodiments S87 and S90, the system is configured to perform the step of acquiring a reference chromatogram prior to the step of executing the automatic optimization procedure. S92. The system according to the previous system implementation form, where the automatic optimization procedure adjusts the time difference t Verz and the adjustment of the time difference t Verz ' includes, where the system is configured to adjust the time difference t Verz and the adjustment of the time difference t Verz ' to carry out. S93. The system according to the previous system implementation form, where the system is configured to perform the adjustment by iterating the adjustment and where the system is configured to perform the iteration until the number of detectable peaks or detectable compounds in a obtained chromatogram is maximized. S94. The system according to one of the preceding system embodiments with the features of embodiment S92, the system is configured to compare the number of detectable peaks or detectable compounds in the obtained chromatogram with the number of detectable peaks or detectable compounds in the reference chromatogram. S95. The system according to one of the preceding system embodiments with the features of embodiment S86, wherein the system is configured to compare the number of detectable peaks or detectable compounds in a obtained chromatogram with the number of detectable peaks or detectable compounds in a reference chromatogram, where this reference chromatogram is provided externally. S96. The system according to one of the three preceding system implementation forms, where the detectable peaks or compounds correspond to peptides, proteins and / or other biomolecules. S97. The system according to one of the preceding system embodiments with the features of embodiment S92, where the system is configured to perform the adjustment by iterating the adjustment and the system is configured to perform the iteration by comparing the peaks in a obtained chromatogram with the peaks in the reference chromatogram until maximum agreement with the reference chromatogram is achieved. S98. The system according to one of the preceding system embodiments with the features of embodiment S92, where the system is configured to perform the adjustment by iterating the adjustment and wherein the system is configured to perform the iteration by comparing the peaks in a obtained chromatogram with the peaks in the reference chromatogram until maximum agreement with the reference chromatogram is achieved, and where this reference chromatogram is provided externally. S99. The system according to one of the preceding system embodiments with the features of embodiment S92, wherein the system is configured to perform the adaptation by iterating the adaptation and wherein the system is configured to perform the iteration at least partially until the number of detectable peaks or detectable compounds in a obtained chromatogram is maximized, and at least partially by comparing the peaks in a obtained chromatogram with the peaks in the reference chromatogram until maximum agreement with the reference chromatogram is achieved. S100. The system according to one of the preceding system embodiments with the features of embodiment S92, where the system is configured to perform the adjustment by iterating the adjustment and wherein the system is configured to perform the iteration at least partially until the number of detectable peaks or detectable compounds in a obtained chromatogram is maximized, and at least partially by comparing the peaks in a obtained chromatogram with the peaks in a reference chromatogram until maximum agreement with that reference chromatogram is achieved, and where this reference chromatogram is provided externally. S101. The system according to one of the preceding system embodiments with the features of embodiments S93 to S100, the system is configured to use peak threshold detection algorithms for peak detection and / or comparison. S102. The system according to the previous system implementation form, where the system is configured to use peak threshold detection based on peak height or signal height. S103. The system according to one of the preceding system embodiments with the features of embodiment S101, wherein the system is configured to use peak threshold detection based on the peak area or signal area. S104. The system according to one of the preceding system embodiments with the features of embodiment S101, where the system is configured to use peak threshold detection based on peak detection algorithms used in the coding sequence. S105. The system according to one of the preceding system embodiments with the features of embodiment S101, the system is configured to use peak threshold detection algorithms that include machine learning techniques. S106. The system according to one of the preceding system embodiments with the features of embodiment S87, where the system is configured to perform the optimization procedure at least partially using a manual optimization procedure. S107. The system according to the previous system implementation form, the system is configured to perform the step of acquiring a reference chromatogram prior to the step of at least partially using the manual optimization procedure. S108. The system according to one of the preceding system embodiments with the features of embodiment S 106, the system is configured to allow a manual optimization procedure which includes the following: Manual definition of a detection window by a user, where the detection window encompasses a time from the start of the detection to the end of the detection, Manual definition by the user of a first and a last eluted compound to be present in an optimized chromatogram, where the optimized chromatogram comprises a chromatogram obtained at the end of the optimization procedure. S109. The system according to one of the preceding system embodiments with the features of embodiments S85 and S108, the system is configured so that the user can define the detection window by manually cutting out a section of interest from a received chromatogram, where the defined detection window is based on the section of interest in the obtained chromatogram, and where the cropping is performed on a dedicated user interface. S110. The system according to one of the preceding system embodiments with the features of embodiment S108, wherein the system is configured to use a mass spectrometer and / or a diode array detector and / or another peak detection instrument to determine the first and last eluted compound present in the user's optimized chromatogram. S111. The system according to one of the preceding system embodiments with the features of embodiment S108, where the system is configured to allow manual adjustment of the time difference t in the manual optimization procedure Verz and the time difference t Verz 'to enable the user, and where the controller is configured to automatically optimize the rest of a workflow. S112. The system according to one of the preceding system embodiments with the features of embodiment S108, wherein the system is configured to allow manual adjustment of the time difference t in the manual optimization procedure. Verzand the time difference t Verz ' to enable the user, and the system is further configured to allow the user to manually adjust the rest of a workflow. S113. The system according to one of the preceding system implementation forms, wherein the flow from the first separation column to the detector in the first configuration (I) has a flow rate in the range of 0 to 10 ml / min, preferably 0 to 100 µl / min, such as 0.1 to 10 µl / min. S114. The system according to one of the preceding system embodiments with the features of embodiment S2, wherein the flow from the second separation column to disposal has a flow rate in the range of 0 to 10 ml / min, preferably 0 to 100 µl / min, such as 0.1 to 10 µl / min. S115. The system according to one of the preceding system embodiments, wherein in the first configuration (I) a pressure provided by the separation pump is in the range of 100 bar to 2,000 bar, preferably 200 bar to 1,500 bar, such as 500 bar to 1,500 bar. S116. The system according to one of the preceding system implementation forms, wherein the controller is configured to control the system to execute the procedure according to one of the preceding procedure implementation forms. S117. The system according to one of the preceding system implementation forms, wherein the system is designed to carry out the procedure set out in one of the preceding method implementation forms. S118. The system according to one of the preceding system implementation forms, wherein the system is designed to perform a specific step of the procedure set forth in one of the preceding procedure implementation forms. S119. The system according to one of the preceding system implementation forms, wherein the system is configured to optimize solvent supply. S120. The system according to the preceding embodiment, wherein optimizing the solvent supply includes optimizing a solvent composition at the start of a gradient supply. S121. The system according to the two preceding embodiments, wherein optimizing the solvent supply comprises optimizing a solvent composition at the end of a gradient supply. S122. The system according to one of the 3 preceding embodiments, wherein optimizing the solvent supply includes optimizing a slope of a gradient supply. The following refers to various forms of use. These forms are abbreviated with the letter "U" followed by a number. Whenever this document refers to "forms of use," these forms are meant. U1. The use of the liquid chromatography system according to one of the preceding system implementations in liquid chromatography. U2. The use according to the preceding embodiment, to carry out the procedure set out in one of the preceding procedural forms. U3. Use in accordance with one of the preceding usage configurations, the pre-column switching valve is used to switch the liquid chromatography system to the first switching time T II to switch from the first configuration to the second configuration. U4. Use in accordance with any of the preceding usage configurations, the post-column switching valve is used to switch the liquid chromatography system to the second switching time T III to switch from the second configuration to the third configuration. U5. Use in accordance with any of the preceding usage configurations, the pre-column switching valve is used to switch the liquid chromatography system to the third switching time T IV to switch from the third configuration to the fourth configuration. U6. Use in accordance with any of the preceding usage configurations, the post-column switching valve is used to switch the liquid chromatography system to the fourth switching time T I to switch from the fourth configuration to the first configuration. U7. Use in accordance with any of the preceding usage configurations, the control is used to automatically execute a workflow according to one of the preceding process execution forms. The following text refers to computer-aided designations. These designations are abbreviated by the letter "C" followed by a number. Whenever "computer-aided designations" are mentioned herein, these designations are meant. C1. A computer program product comprising instructions which, when executed by a processor, cause the processor to control a liquid chromatography system to perform the procedure according to one of the preceding procedure implementation forms. C2. A computer-readable medium comprising instructions which, when executed by a processor, cause the processor to control a liquid chromatography system to carry out the procedure according to one of the preceding procedure implementations. C3. A data carrier signal carrying the computer program product of embodiment C1. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 illustrates exemplary chromatograms of a liquid chromatography system for different values ​​of the time difference between the start of the gradient feed and the start of detection in the liquid chromatography system. Fig. Figure 2 represents, by way of example, a preferred embodiment of a liquid chromatography system according to an embodiment of the present invention in a first configuration which may be referred to as the “first steady state”; Fig. Figure 3 presents, as an example, a preferred embodiment of the system of Fig. 2 in a second configuration, which can be described as the "first intermediate state"; Fig. Figure 4 presents, as an example, a preferred embodiment of the system of Fig. 2 in a third configuration, which can be referred to as the “second stationary state”; Fig. Figure 5 presents, as an example, a preferred embodiment of the system of Fig. 2 in a fourth configuration, which can be described as the "second intermediate state"; Fig. Figure 6 presents an exemplary visualization of a workflow of a tandem liquid chromatography system with an optimized acquisition time window based on four configurations of the tandem liquid chromatography system; Fig. Figure 7 illustrates, as an example, UV chromatograms of cytochrome C, which show the influence of the time difference between the start of detector detection and the start of gradient feed in a liquid chromatography system on UV chromatograms of cytochrome C. Fig. Figure 8 presents, as an example, preferred embodiments of a liquid chromatography system that uses a double-tube electrospray source and adopts four configurations according to embodiments of the present invention. DETAILED DESCRIPTION OF THE DRAWINGS

[0285] It should be noted that not all drawings include all reference symbols. In some drawings, some reference symbols have been omitted for the sake of brevity and clarity.

[0286] Exemplary embodiments of the present invention are described in detail below with reference to the accompanying figures.

[0287] While preferred embodiments of the present invention are described below, those skilled in the art understand that the preferred embodiments are provided only for illustrative purposes and to complete the disclosure of the present invention and should in no case be construed as limiting the scope of protection of the present invention as defined by the claims.

[0288] In general terms, embodiments of the present invention relate to the implementation of a workflow in conjunction with a liquid chromatography (LC) system. These embodiments relate to the implementation of a workflow in a tandem liquid chromatography system characterized by the use of two pumps and two separation columns.

[0289] To perform liquid chromatography (LC), a sample is generally subjected to a flow through a separation column and towards a detector by means of a pump. The pump used in a liquid chromatography system can introduce a gradient into the separation column. This means that the composition of the mobile phase can be changed over time by the pump. Furthermore, the mobile phase can traverse the column in a specific time interval. This time interval can depend on the volume of the column, the fluid connection between the column and the pump, and the flow rate of the pump. In other words, the gradient introduced at the pump at a given time can differ from the gradient introduced at the detector at the same time.For example, if the gradient supply is just being started by the pump, the gradient supply at the pump is equal to the initial gradient supply, while the gradient supply at the detector at a later time will be equal to the initial gradient supply.

[0290] In many state-of-the-art LC systems, the detector is configured to start the detection window when the pump begins feeding the gradient into the separation column. However, this workflow prevents optimal use of the detection window because the detector is actively used from the moment the pump starts feeding the gradient. In other words, the detector is actively used from the moment the gradient feed at the separation pump equals the initial gradient, and not only when the gradient feed at the detector equals the initial gradient.

[0291] The present invention relates at least in part to a workflow in which the time difference between the start of the gradient feed and the start of the detection differs significantly from zero and can be optimized.

[0292] Fig. Figure 1 illustrates exemplary chromatograms of a liquid chromatography system for different values ​​of the time difference between the start of gradient injection and the start of detection in the liquid chromatography system. In other words, the effect of the different values ​​of this time difference is illustrated.

[0293] Fig. Figure 1A shows an example of a periodic temporal variation of the gradient supply at pump 14. In general, a pump can supply a gradient during a liquid chromatography procedure. That is, the solvent composition can change over time. For example, different solvents A and B can be mixed in different ratios. Fig. 1 A) (as Fig. Figure 1 B)) shows the volume fraction of solvent B in the solvent mixture over time. As in Fig. As shown in Figure 1A), the amount of solvent B increases monotonically at different rates, is then held constant, and then decreased again during run I (see section 15); however, it is understood that this is merely an example and that other solvent compositions can also be used over time. The subsequent runs i+1 and i+2 have a corresponding solvent composition that is supplied over time. In this embodiment, the start of the gradient supply at pump 14 can coincide with the start of sample run 15. The gradient supply at pump 14 at the start of sample run 15 can essentially correspond to the initial gradient supply 16. Similarly, the gradient supply at pump 14 at the end of sample run 15 can essentially correspond to the ending gradient supply 17. Sample run 15 can be followed by further sample runs.

[0294] Generally speaking, it goes without saying that Fig. 1 A) represents the solvent composition at the pump, which can also be called a chromatography pump or separation pump. Furthermore, it is understood that the solvent composition at a detector downstream of the pump differs from the solvent composition at the pump. In particular, there is usually a time delay or detail time t. Verz between the two. For example, it is taken into account that the pump supplies the fluid at a flow rate of 10 µl / min, and it is further taken into account that the fluid path between the pump (e.g., connecting hoses, column, valves) has a total internal volume of 20 µl. In this example, any change in the solvent composition at the pump would only reach the detector after 2 minutes.

[0295] This is in Fig. 1 B) visible. Fig. Figure 1B shows the solvent composition over time at the detector. In simplified terms, this solvent composition corresponds to the solvent composition at the detector, but there is a time delay t between the two. Verz before. In other words, shows Fig. 1 B) an exemplary periodic time course of the gradient feed at detector 18. It is understood that the time difference t Verz 19 between the time at which the detector starts detection and the time at which the gradient feed to pump 14 starts, is usually not equal to zero.

[0296] Fig. Figure 1C shows exemplary chromatograms without taking into account the delay time t. Verz, i.e., in the case where the acquisition time windows 20 were chosen to coincide with the gradient runs supplied by the gradient pump (see 15). In this example, there are three acquisition time windows 20a, 20b, and 20c that coincide with the gradient supply runs i, i+1, and i+2 at the pump. Due to the time delay t Verz The acquisition time windows are not ideal. In particular, there is a section at the beginning of the first acquisition time window 20a in which the gradient supplied by the pump has not yet reached the detector. Furthermore, there is a section 21 at the beginning of the second acquisition time window 20b in which the gradient (and thus also the sample) from run i is still arriving at the detector. That is, this section 21 actually corresponds to run i, but is (based on Fig. 1 C) explained example) part of the data collection time window 20a. It is understood that similar considerations also apply to the data collection time window 20c in Fig. 1 C) apply.

[0297] Fig. Figure 1D shows exemplary chromatograms when the data acquisition time window is 20' and the delay time is t Verz Please note that the data acquisition time windows 20' are shifted in the time domain with respect to the gradient runs 15 at the pump. Thus, section 21' is correctly assigned to the first run. Furthermore, with regard to the Fig. 1 B) and Fig. 1 D) to determine that the data acquisition time windows correspond to the gradient when it is fed to the detector.

[0298] In general, in embodiments of the present invention, the data acquisition time windows at the detector can be shifted with respect to the analysis runs (or more precisely, gradient runs) supplied by the pump. This shift explains the time delay t. Verz , i.e., the time the solvent takes to travel from the pump to the detector. It should be noted that better and more reproducible chromatograms are generally produced when the delay time is taken into account by shifting the data acquisition time windows as described.

[0299] In tandem LC applications, workflows can typically be highly optimized for high throughput to obtain one chromatogram immediately after another. Therefore, the size / duration of the elution window can account for a significant portion of the gradient time. Under these conditions, fractions of the compounds of interest may be missing from the chromatogram. This is the case, for example, in Fig. Figure 1C illustrates this. Additionally, the resulting chromatogram may consist of compounds partially eluted from one column and partially from another; this may not be intentional, as the chromatogram would not be strictly assigned to a single run or even a single sample. This is the case, for example, in Fig. 1C illustrates this. Therefore, it can be advantageous to t Verz to optimize.

[0300] It is understood that embodiments of the approach presented herein allow for the optimization of the elution window position in the time domain, i.e., the period during which compounds of interest are eluted from the separation column, in order to achieve high sample throughput and uncompromising chromatographic performance. This can be achieved by adjusting the start of detector data acquisition relative to the gradient start, as described in Fig. 1 illustrates.

[0301] Fig. Figure 2 represents, by way of example, a preferred embodiment of a liquid chromatography system according to an embodiment of the present invention in a first configuration I.

[0302] Embodiments of the present invention may be directed towards the use of a tandem liquid chromatography system in which two separation columns and two pumps are used. The liquid chromatography system may, as in Fig. Figure 2 illustrates a first separation column 8, a second separation column 5, a separation pump 1, a purification pump 12, and a detector 22. The first and second separation columns can be housed in a column chamber 2. The system can include an autosampler 3, which may include an injection valve 10. The liquid chromatography system can further include a pre-column switching valve 13 and a post-column switching valve 7. The pre-column switching valve 13 and the post-column switching valve 7 can be housed in the column chamber 2. The liquid chromatography system can include a disposal system.

[0303] The injection valve 10, the upstream switching valve 13, and the downstream switching valve 7 can each comprise a stator, a rotor, and a rotary actuator. Each stator can include a variety of ports that allow different elements in the liquid chromatography system to be fluidically connected. Each rotor can include connecting elements, such as slots, that can fluidically connect different ports of the stator. The rotor can be rotated relative to the stator by means of the rotary actuator, allowing the connecting elements of the rotor to establish fluid connections between different ports of the stator.

[0304] One port of the injection valve 10 can have a fluid connection 9 to a port of the upstream column switching valve 13. Another port of the injection valve 10 can have a fluid connection 11 to the treatment pump 12. The port of the injection valve 10 that can have a fluid connection 9 to a port of the upstream column switching valve 13, and the port of the injection valve 10 that can have a fluid connection 11 to the treatment pump 12, can be connected by means of the connecting elements of the injection valve 10 in the configuration of Fig. 2. be fluidically connected. Furthermore, one or more ports of the injection valve 10 can have a fluid connection to one or more sample containers, which contain one or more samples.

[0305] One connection of the upstream column switching valve 13 can have a fluid connection 4 to the separation pump 1; another connection of the upstream column switching valve 13 can have a fluid connection to the first separation column 8; another connection of the upstream column switching valve 13 can have a fluid connection to the second separation column 5.

[0306] One port of the post-column switching valve 7 can have a fluid connection 6 to the detector 22; another port of the post-column switching valve 7 can have a fluid connection to the first separation column 8; another port of the post-column switching valve 7 can have a fluid connection to the second separation column 5; another port of the post-column switching valve 7 can have a fluid connection to a disposal.

[0307] The configuration adopted by the upstream switching valve 13 and the downstream switching valve 7 can determine the fluid connection between different elements of the chromatography system, or, in other words, the configuration of the liquid chromatography system. In particular, the configuration of the connecting elements of the upstream switching valve 13 and the downstream switching valve 7 determines the configuration of the liquid chromatography system.

[0308] For example, in Fig. 2 An embodiment of the liquid chromatography system according to the present invention is shown in a first configuration I.

[0309] The connection of the pre-column switching valve 13, which may have a fluid connection to a connection of the injection valve 10, and the connection of the pre-column switching valve 13, which may have a fluid connection to the second separation column 5, may be fluidically connected by means of the connecting elements of the pre-column switching valve 13 in the first configuration I. The connection of the pre-column switching valve 13, which may have a fluid connection to the separation pump 1, and the connection of the pre-column switching valve 13, which may have a fluid connection to the first separation column 8, may be fluidically connected by means of the connecting elements of the pre-column switching valve 13 in the first configuration I.

[0310] The connection of the post-column switching valve 7, which may have a fluid connection to the first separation column 8, and the connection of the post-column switching valve 7, which may have a fluid connection to the detector 22, may be fluidically connected by means of the connecting elements of the post-column switching valve 7 in the first configuration I. The connection of the post-column switching valve 7, which may have a fluid connection to the second separation column 5, and the connection of the post-column switching valve 7, which may have a fluid connection for disposal, may be fluidically connected by means of the connecting elements of the post-column switching valve 7 in the first configuration I.

[0311] According to a preferred embodiment, the present invention is at least partially directed to direct a flow from the first separation column 8 into the detector 22 by means of the separation pump 1 in the first configuration I, as in the preferred embodiment of Fig. Figure 2 shows the first configuration I, which can be called the "first steady state". In the first configuration I, the separation pump establishes a flow from the first separation column 8 to the detector 22.

[0312] According to a preferred embodiment, the present invention is at least partially also directed to direct a flow from the second separation column 5 to disposal by means of the processing pump 12 in the first configuration I.

[0313] The procedure can further include injecting a sample into the liquid chromatography system via the injection valve 10 and pushing the sample into the second separation column 5 using the preparation pump 12 in the first configuration I.

[0314] Fig. Figure 3 presents, as an example, a preferred embodiment of the system of Fig. 2 in a second configuration II.

[0315] The connection of the pre-column switching valve 13, which can be fluidically connected to a connection of the injection valve 10, and the connection of the pre-column switching valve 13, which can be fluidically connected to the first separation column 8, can be fluidically connected in the second configuration II by means of the connecting elements of the pre-column switching valve 13. The connection of the pre-column switching valve 13, which can have a fluid connection to the separation pump 1, and the connection of the pre-column switching valve 13, which can have a fluid connection to the second separation column 5, can be fluidly connected in the second configuration I by means of the connecting elements of the pre-column switching valve 13.

[0316] The connection of the post-column switching valve 13, which may have a fluid connection to the first separation column 8, and the connection of the post-column switching valve 13, which may have a fluid connection to the detector 22, may be fluidically connected in the second configuration II by means of the connecting elements of the post-column switching valve. The connection of the post-column switching valve 13, which may have a fluid connection to the second separation column 5, and the connection of the post-column switching valve 13, which may have a fluid connection for disposal, may also be fluidically connected in the second configuration II by means of the connecting elements of the post-column switching valve 13.

[0317] The present invention is at least partially directed to direct a flow from the first separation column 8 into the detector 22 in the second configuration II by means of the processing pump 12, as in the preferred embodiment of Fig. 3 shown. The second configuration II can be referred to as the “first intermediate state”, in which the processing pump 12 establishes a flow from the first separation column 8 into the detector 22.

[0318] The present invention is at least partially also directed to direct a flow from the second separation column 5 into the disposal system by means of the separation pump 1 in the second configuration I, as in the preferred embodiment of Fig. 3 shown.

[0319] The present invention, in the second configuration II, also aims at least partially at injecting a sample into the liquid chromatography system via the injection valve 10 and pressing the sample into the first separation column 8 by means of the preparation pump 12.

[0320] Fig. Figure 4 presents, as an example, a preferred embodiment of the system of Fig. 2 in a third configuration.

[0321] The connection of the pre-column switching valve 13, which may have a fluid connection to a connection of the injection valve 10, and the connection of the pre-column switching valve 13, which may have a fluid connection to the first separation column 8, may be fluidically connected in the third configuration by means of the connecting elements of the pre-column switching valve 13. The connection of the pre-column switching valve 13, which may have a fluid connection to the separation pump 1, and the connection of the pre-column switching valve 13, which may have a fluid connection to the second separation column, may be fluidically connected in the third configuration III by means of the connecting elements of the pre-column switching valve 13.

[0322] The connection of the post-column switching valve 13, which may have a fluid connection to the first separation column 8, and the connection of the post-column switching valve 13, which may have a fluid connection for disposal, may be fluidically connected in the third configuration III by means of the connecting elements of the post-column switching valve 13. The connection of the post-column switching valve 13, which may have a fluid connection to the second separation column 5, and the connection of the post-column switching valve 13, which may have a fluid connection to the detector 22, may also be fluidically connected in the third configuration III by means of the connecting elements of the post-column switching valve 13.

[0323] The present invention is at least partially directed to direct, in the third configuration III, a flow from the first separation column 8 to the disposal system by means of the processing pump 12, as in the preferred embodiment of Fig. 3 shown.

[0324] The present invention is at least partially also directed to direct a flow from the second separation column 5 into the detector 22 in the third configuration III by means of the separation pump 1, as in the preferred embodiment of Fig. 3 shown. The third configuration III can be referred to as the “second steady state”, in which the separation pump 1 establishes a flow from the second separation column 5 into the detector 22.

[0325] The present invention, in the third configuration III, also aims at least partially at injecting a sample into the liquid chromatography system via the injection valve 10 and pressing the sample into the first separation column 8 by means of the preparation pump 12.

[0326] Fig. Figure 5 presents, as an example, a preferred embodiment of the system of Fig. 2 in a fourth configuration.

[0327] The connection of the pre-column switching valve 13, which can be fluidically connected to a connection of the injection valve 10, and the connection of the pre-column switching valve, which can be fluidically connected to the second separation column 5, can be fluidically connected in the fourth configuration IV by means of the connecting elements of the pre-column switching valve 13. The connection of the pre-column switching valve 13, which can have a fluid connection to the separation pump 1, and the connection of the pre-column switching valve 13, which can have a fluid connection to the first separation column 8, can be fluidly connected in the fourth configuration IV by means of the connecting elements of the pre-column switching valve 13.

[0328] The connection of the post-column switching valve 13, which may have a fluid connection to the first separation column 8, and the connection of the post-column switching valve 13, which may have a fluid connection for disposal, may be fluidically connected in the fourth configuration IV by means of the connecting elements of the post-column switching valve 13. The connection of the post-column switching valve 13, which may have a fluid connection to the second separation column 5, and the connection of the post-column switching valve 13, which may have a fluid connection to the detector 22, may be fluidically connected in the fourth configuration III by means of the connecting elements of the post-column switching valve 13.

[0329] The present invention is at least partially directed to direct, in the fourth configuration IV, a flow from the first separation column 8 to the disposal system by means of the separation pump 1, as in the preferred embodiment of Fig. 4 shown.

[0330] The present invention is at least partially also directed to direct a flow from the second separation column 5 into the detector 22 in the fourth configuration IV by means of the processing pump 12, as in the preferred embodiment of Fig. 4 shown. The fourth configuration IV can be referred to as the “second intermediate state”, in which the processing pump 12 establishes a flow from the second separation column 5 into the detector 22.

[0331] The present invention, in the fourth configuration IV, also aims at least partially at injecting a sample into the liquid chromatography system via the injection valve 10 and pressing the sample into the second separation column 5 by means of the preparation pump 12.

[0332] Furthermore, the system can, as in Fig. 2, Fig. 3, Fig. 4 and Fig. 5 shown, also includes a controller 42. The controller 42 can be functionally connected to other components, as shown in Fig. 2, Fig. 3, Fig. 4 and Fig. Figure 5 is represented by dashed lines. For example, the controller 42 can be functionally connected to the processing pump 12, the injection valve 10, the detector 22, the post-column switching valve 7, any component that serves at least a partially similar purpose to the column switching valve 7, the separation pump 1, and the pre-column switching valve 13. The controller 420 can include a data processing unit and can be configured to control the system and execute certain process steps. The controller can send or receive electronic signals for instructions. The controller can also be referred to as a microprocessor. The controller can be contained on an integrated circuit chip. The controller can include a processor with memory and associated circuitry.A microprocessor is a computer processor that incorporates the functions of a central processing unit on a single integrated circuit (IC) or sometimes on a multitude of ICs, such as eight ICs. The microprocessor can be a general-purpose, clock-controlled, register-based, digitally integrated circuit that accepts binary data as input, processes it according to instructions stored in its memory, and provides results (also in binary form) as output. Microprocessors can incorporate both combinational logic and sequential digital logic. Microprocessors operate with numbers and symbols represented in the binary number system.

[0333] Fig. Figure 6 presents an exemplary visualization of a workflow of a tandem liquid chromatography system with an optimized acquisition time window based on four configurations of the tandem liquid chromatography system.

[0334] The present invention relates at least in part to the use of a workflow for tandem direct injection of a liquid chromatography system with an optimized elution time window and an optimized detection time window, based on the four configurations of the preferred embodiments of Fig. 2 to Fig. 5.

[0335] In particular, the elution window and the detector data acquisition window can be optimized to obtain consistent, reproducible chromatograms at optimal throughput, without losing relevant sections of the chromatogram. This approach can be especially advantageous for tandem LC applications.

[0336] In particular, four moments can be of temporal significance: a first switching point T II , a second switching point T III , a third switching point T IV and a fourth switching point T I , where T I night IV lies, which after T III lies, which after T II lies. The system can at the first switching time T II The system can be switched from the first configuration I to the second configuration II. III The system can be switched from the second configuration II to the third configuration III. IV The system can be switched from the third configuration III to the fourth configuration IV. IThe system switches from the fourth configuration IV back to the first configuration I. In other words, the invention relates to a process in which the system switches between four configurations. This process can be a cyclical process, i.e., a process that repeats itself.

[0337] The system can be switched, in particular, from a "steady-state" of the first configuration I to an "intermediate state" of the second configuration II, then to a "steady-state" of the third configuration III, and subsequently to an "intermediate state" of the fourth configuration IV. It is understood that a "steady-state" of the liquid chromatography system identifies a state in which the separation pump 1 provides a flow through the first column 8 or the second column 4 into the detector. It is also understood that a "temporary" state of the liquid chromatography system identifies a state in which the preparation pump 12 provides a flow through the first column 8 or the second column 4 into the detector.

[0338] The time difference between T III and T II can with t Verz be identified. The time difference between T I and T IV can also be used with t Verzbe identified.

[0339] Regarding the preferred embodiment of Fig. 6. The liquid chromatography system should be in the first configuration I immediately before T. II are located at T II The upstream column switching valve 13 can switch the system from the first configuration I to the second configuration II. At T II A fluid connection can be established between the separation pump 1, the second separation column 5 and the disposal system.

[0340] In other words, at T IIThe pre-column switching valve 13 is switched to direct the simultaneously initiated gradient flow to the freshly prepared second separation column 5. At the same time, the reprocessing pump 12 can feed the last fraction of the gradient, which may have been generated by the separation pump 1 in a previous step of the cycle through the first separation column 5, to the post-column switching valve 7, where it can be directed to the detector 22. There, the compounds that may have been eluted from this last fraction of the gradient can be detected. During this phase, the flow rate of the reprocessing pump 12 can preferably be identical to the gradient flow rate of the separation pump 1 to ensure a uniform flow of the gradient solvents to the detector 22.

[0341] The separation pump 1 can be used at T IIstarting with the provision of a gradient, which initiates an elution window. However, the detector may not yet start a new acquisition window 38. This is because the gradient, which is generated at T II Once started, it may take a certain amount of time to pass through the fluid connections between the separation pump 1 and the second separation column 5 and then through the second separation column 5.

[0342] At T II Furthermore, a fluid connection can be established between the processing pump 12, the autosampler 3, the first separation column 8 and the detector 22.

[0343] The processing pump 12 can provide a flow from the first separation column 8 into the detector 22. During this phase, which can be described as "waiting," the processing pump 12 can push the contents of the first separation column 8 into the detector 22. The flow rate of the processing pump can correspond to that of the separation pump during this phase. The detector 22 starts at T II Under certain circumstances, no new detection window 38 is opened, but the detection continues in a previous detection window and, in particular, continues to detect the flow provided from the first separation column 8 by means of the processing pump 12. The detector can also continue detection after T II and before T III Stop, which ends the previous capture window, and start a new capture window until T III wait.

[0344] At T IIIThe post-column switching valve 7 can switch the system from the second configuration II to the third configuration III.

[0345] At T III A fluid connection can be established between the separation pump 1, the second separation column 5 and the detector 22.

[0346] The separation pump 1 may be used at T II have started with the provision of the gradient. Therefore, at T III The gradient provided by the separation pump may take time to circulate through the fluid connections between the separation pump 1 and the second separation column 5, and then through the second separation column 5, and finally through the fluid connection between the second separation column 5 and the detector 22. Therefore, at T III The detector 22 starts the detection in a detection window 38.

[0347] At T IIIFurthermore, a fluid connection can be established between the processing pump 12, the autosampler 3, the first separation column 8 and the disposal system.

[0348] The treatment pump 12 can provide a flow from the first separation column 8 to the disposal. During this phase, the treatment pump 12 treats the first separation column 8. The flow rate of the treatment pump 12 can be greater than that of the separation pump 1 during this phase. It is understood that the autosampler 3 at T II can start the injection of a sample into the liquid chromatography system and the injection of the sample into the liquid chromatography after T III and before T IV can end.

[0349] In other words, at T III , which at t Verz night IThe post-column switching valve 7 may be switched, and the flow from the second separation column 5, which may contain solvent under a gradient start condition (for example, 16), may be directed to the detector 22. In the case of the processing pump 12, the processing pump 12 will be switched on at time T. III , who at t Verz night I The last fraction of the gradient, representing the final gradient concentration (e.g., 17), may have been fed to the detector 22 via the post-column switching valve 7. The preparation of the first separation column 8 can now begin. For this purpose, the flow rate of the preparation pump 12 can be increased to accelerate the washing and equilibration of the first separation column 8. At the post-column switching valve 7, the flow can be directed to a disposal container.

[0350] It should be noted that if a mass spectrometry detector with a double-tube electrospray source is used for detection instead of a post-column switching valve 7, a switching of the high voltage between the two electrospray sources could also be used analogously to switching the post-column switching valve 7.

[0351] Embodiments with regard to the use of a mass spectrometry detector with a double-tube electrospray source for detection instead of a post-column switching valve 7 are described with regard to Fig. 8 discussed.

[0352] At T IV The upstream column switching valve 13 can switch the system from the third configuration III to the fourth configuration IV.

[0353] At T IV A fluid connection can be established between the separation pump 1, the first separation column 8 and the disposal system.

[0354] The separation pump 1 can be used at T IVThe gradient is then applied, initiating an elution window. However, the detector may not yet start a new detection window. This is because the gradient may require some time to circulate through the fluid connections between separation pump 1 and the first separation column 8, and then through the first separation column 8 itself.

[0355] At T IV Furthermore, a fluid connection can be established between the processing pump 12, the autosampler 3, the second separation column 5 and the detector 22.

[0356] The processing pump 12 can provide a flow from the second separation column 5 into the detector 22. During this phase, which can be described as "waiting", the processing pump 12 can push the contents of the second separation column 5 into the detector 22.

[0357] In other words, the last fraction of the gradient, which starts from separation pump 1 into the second separation column 5 from T II will start from T IV The sample is eluted into the detector by the processing pump 12. The flow rate of the processing pump 12 can be the same as that of the separation pump 1 during this phase.

[0358] The detector 22 may be used at T IV The detector 22 does not start a new detection window, but instead must continue with the detection and, in particular, continue to detect the flow from the second separation column 5, which is supplied by the processing pump 12. In other words, the detector 22 can detect the last fraction of the gradient supplied by the separation pump 1 to the second separation column 5 from T II continue. The detector can also continue detection after T IV stop, which ends the capture window 38, and before T IStop and start a new capture window until T I wait.

[0359] At T I The post-column switching valve 7 can switch the system from the fourth configuration IV back to the first configuration I.

[0360] At T I A fluid connection can be established between the separation pump 1, the first separation column 8 and the detector 22.

[0361] The separation pump 1 can be used at T IV start the gradient provisioning. Therefore, at T I The gradient provided by the separation pump 1 may take time to pass through the fluid connections between the separation pump 1 and the first separation column 8, and then through the first separation column 8, and finally through the fluid connection between the first separation column 8 and the detector 22. Therefore, the detector 22 may be at T I Start the detection in a new capture window.

[0362] At T IFurthermore, a fluid connection can be established between the processing pump 12, the autosampler 3, the second separation column 5 and the disposal system.

[0363] The treatment pump 12 can provide a flow from the second separation column 5 to the disposal. During this phase, the treatment pump 12 treats the second separation column 5. The flow rate of the treatment pump 12 can be higher than that of the separation pump 1 during this phase. It is understood that the autosampler 3 at T I can start the injection of a sample into the liquid chromatography system.

[0364] It goes without saying that the system according to T I the embodiment of Fig. Repeat the process described in 6 periodically, at a time T II ', who after T IThe system can switch from the first configuration I to the second configuration II. In other words, a cyclical process can be implemented by the system, switching between four configurations.

[0365] The subsequent cycle follows the same temporal sequence, so that the times T II ', T III ', T IV ', T I ' of the following cycle at the respective time points T II , T III , T IV , T, both in terms of temporal and functional properties.

[0366] Furthermore, the present invention relates at least partially to the optimization of the time difference t. Verz between T III and T II and between T I and T IV directed. The optimization of the time difference t VerzFor example, in a tandem chromatography system, this can lead to consistent and reproducible chromatograms, where a single detection window can only contain all of the chromatographic peaks of a single compound and / or group of compounds of interest. Optimizing the time difference t Verz Furthermore, it can, for example, lead to an optimal throughput of the tandem chromatography system.

[0367] In other words, due to the optimized delay between T III and T II and between T I and T IV The detector detection window is optimally adjusted to the time at which the individual compound and / or the group of compounds of interest reach the detector.

[0368] In general, embodiments of the present invention can be described as follows. Fig. Figure 2 represents a liquid chromatography system in a first configuration I. In this configuration, the separation pump 1 is connected to the first separation column 8 and further to the detector 22. Furthermore, the purification pump 12 is connected to the second separation column 5 and a disposal system (in Fig. (1 not shown) fluidically connected. This is a “normal” or steady state, in which the second separation column 5 can be prepared and the separation pump 1 can provide a gradient to the first separation column 8 and further to the detector 22.

[0369] It goes without saying that Fig. 4 represents another “normal” or stationary state in which the separation pump 1 is connected to the second separation column 5 and the detector 22 and the processing pump 12 is connected to the first separation column 8 and the disposal.

[0370] Embodiments of the present invention are directed such that the system additionally also includes the Fig. 3 depicted state or configuration II and / or the one in Fig. 5 shown IV assumes. In configuration II in Fig. 3 is the processing pump 12, which can also be referred to as the second pump 12, connected to the first separation column 8 and the detector 22. That is, unlike in the Fig. 2 and Fig. In addition to the 4 configurations shown, I and III, the system also assumes a configuration in which the second pump 12 is connected to the detector.

[0371] The system will be activated at a first switching time T II from configuration I in Fig. 2 to configuration II in Fig. 2 switched, where the index indicates the configuration to which the system switches. At the first switching time T IIIt is preferred that the solvent composition and the flow rate supplied by the second pump 12 are identical to those supplied by the separation pump 1. It is understood that the flow rate and the solvent composition should be identical to those supplied at the pre-column switching valve 13, since this is where the change in fluid composition takes effect.

[0372] As discussed above, there is generally a delay time t. Verz between the time at which a specific solvent composition is present at the separation pump 1 (within the framework of gradient operation) and the time at which this solvent composition arrives at the detector 22. In embodiments of the present invention, the system is configured in configuration II of Fig. 3 operated for a duration equal to this delay time t Verz This corresponds to a duration t. VerzFluid from the first separation column 8 is fed to the detector 22 by means of the second pump 12.

[0373] This is also in Fig. Figure 6 shows that the upstream column switching valve 13 is activated at time T. II switched on. The processing pump 12 then "waits" for the delay time t. Verz , i.e., it is used to create a flow from the first separation column 8 to the detector 22. During this time, data acquisition takes place, followed by a short waiting period at the detector 22.

[0374] Once the last part of the gradient reaches detector 22, the system switches from configuration II to Fig. 3 to configuration III in Fig. 4 switched. In this configuration, the first separation column 8 is connected to the processing pump 12 and the disposal system. Furthermore, the second separation column 5 is connected to the separation pump 12 and the detector 22. Regarding separation column 5, we again refer to configuration II of Fig. 3 referred to. In this configuration II, the second separation column 5 is already connected to the separation pump 1. However, it is not yet connected to the detector 22, but to the waste disposal system. In this configuration, the separation pump 1 can be connected with its gradient feed (see Fig. 6 at the first switching time T II ) start. Here too, it is understood that a solvent composition supplied by the separation pump at a specific time will only reach the downstream components later. In particular, this solvent composition may have a delay time t at the start of the gradient feed. Verzrequired to reach the downstream switching valve. Only at this point can the solvent present at the downstream switching valve be of interest for further detection. Thus, at the second switching time T III , which is about the delay time t Verz after the first switching time T II lies, the system of the second configuration II of Fig. 3 to the third configuration III of Fig. 4. At this point, a new data collection time window can start (see 38 in Fig. 6), which corresponds to the gradient supplied by the separation pump 1, arriving at the detector 22.

[0375] Furthermore, it is pointed out that in configuration III of Fig. 4. The first separation column 8 is no longer connected to the detector 22, but to the disposal system. In this configuration, the first separation column 8 can therefore be processed. This is in Fig. Figure 6 shows where the processing pump 12 starts from the third switching point T III A column preparation is provided. It is understood that this column preparation can be carried out at flow rates that differ from the flow rate at which the gradient is fed. In particular, it can be carried out at higher flow rates. After the first separation column 8 has been prepared, it can be loaded with another sample. In addition, the preparation pump 12 can be started before the third switching time T. IV to carry out a voting step.

[0376] In this respect, it goes without saying that the in Fig. The fourth configuration IV, shown in section 5, is essentially the same as the one described in [section / document]. Fig. The second configuration II shown in Figure 3 corresponds to this, but with the roles of the first separation column 8 and the second separation column 5 reversed. Here too, the second separation column 5, as in configuration III assumed before configuration IV, is connected to the separation pump 1 and the detector 22. In configuration IV (see Figure 3) Fig. 5) The second separation column 5 remains connected to the detector 22, but no longer to the separation pump 1, instead to the processing pump 12. Similar to the configuration in Fig. 3 causes the processing pump 12 to ensure that the last sections of the gradient flow from the second separation column 5 to the detector 22. Here too, it can be advantageous if the operating parameters of the solvent, which is added at the third switching time T IV is provided, i.e., when the system is in the Fig. Configuration IV, as shown in section 5, is identical for the separation pump 1 and the second pump 12, which can also be referred to as the treatment pump 12. It is also understood that when switching to the fourth configuration IV in Fig. 5. The processing pump 12 assumes the function of the separation pump 1 in configuration IV. Therefore, it is advantageous if the operating parameters (especially flow rate and solvent composition) are at switching time T. IV are identical. Therefore, before the switching time T IV (see Fig. 6) the processing pump 12 and the separation pump 1 are coordinated with each other, i.e. their operating parameters are at switching time T IV identical. At T IV The upstream column switching valve is switched so that configuration IV of Fig. 5 is assumed.

[0377] This configuration IV also essentially corresponds to configuration II of Fig. 3, where the roles of the separating columns 5 and 8 are reversed. It is therefore understood that the system at a fourth switching time T I back to the in Fig. 2. Configuration I shown can be switched and the overall operation can be cyclically performed between configurations I, II, III and IV.

[0378] With regard to Fig. 6. The following must be taken into account. First, as described, the fluid is directed to the detector 22 via both the separation pump 1 and the conditioning pump 12 (see fields labeled "Wait" for the conditioning pump 12 in Fig. 6 and configurations II and IV, in which the processing pump 12 is connected to the detector 22). Secondly, the detection time windows 38 are determined with regard to the gradient feed of the separation pump 1 (see Fig. 6) postponed to account for the time delay t Verzto take into account the difference between the supply of a specific solvent composition by the pump and its arrival at detector 22.

[0379] Overall, embodiments of the present technology thus enable an increased service life of the described system. In particular, compared to other configurations, samples containing solvents can be fed to detector 22 more frequently. Furthermore, by shifting the data acquisition time windows, signals from a specific sample can be assigned more precisely than would be possible without such a shift.

[0380] Fig. Figure 7 illustrates, as an example, UV chromatograms of cytochrome C, which show the influence of the time difference between the start of detector acquisition and the start of gradient supply in a liquid chromatography system on UV chromatograms of cytochrome C.

[0381] More precisely, in Fig. 7. Using the example of a UV chromatogram of cytochrome C, the elution window and thus the resulting chromatogram are shifted stepwise to the left by adjusting the start of detector detection relative to the start of gradient supply.

[0382] The grey areas of the chromatograms of the embodiment of Fig. 7 indicates regions of the chromatograms that are not within the detection window. The complete UV chromatogram of cytochrome c can show fifteen peaks, with the first peak at 23 and the last peak at 37 in the sequence.

[0383] Fig. Figure 7A represents a UV chromatogram of cytochrome c, measured with a delay of zero minutes between the start of detector acquisition and the start of gradient feed in a liquid chromatography system. In this case, the last peaks 35, 36, and 37 in the peak sequence of the complete UV chromatogram of cytochrome c may not be included in the detection window.

[0384] Fig. Figure 7B represents a UV chromatogram of cytochrome c, measured with a delay of one minute between the start of detector acquisition and the start of gradient feed in a liquid chromatography system. In this case, the last peaks are 36 and 37 (see Figure 7B). Fig. 7D) in the peak sequence of the complete UV chromatogram of cytochrome C may not be included in the detection window.

[0385] Overall, peaks at the "far end" (i.e., at high retention times) of the chromatogram may be absent, as shown in Fig. 7A and Fig. 7B illustrates this.

[0386] Fig. 7C represents a UV chromatogram of cytochrome c, measured with a delay of three minutes between the start of detector acquisition and the start of gradient feed in a liquid chromatography system. In this case, all peaks in the peak sequence of the complete UV chromatogram of cytochrome c may be included in the detection window.

[0387] Fig. 7D represents a UV chromatogram of cytochrome c, measured with a delay of four minutes between the start of detector acquisition and the start of gradient feed in a liquid chromatography system. In this case, all peaks in the peak sequence of the complete UV chromatogram of cytochrome c may be included in the detection window.

[0388] Fig. 7E represents a UV chromatogram of cytochrome c, measured with a five-minute delay between the start of detector acquisition and the start of gradient feed in a liquid chromatography system. In this case, all peaks in the peak sequence of the complete UV chromatogram of cytochrome c may be included in the detection window.

[0389] Overall, all peaks in the chromatogram can be present, as shown in Fig. 7C, Fig. 7D and Fig. 7E illustrates.

[0390] Fig. Figure 7F represents a UV chromatogram of cytochrome c, measured with a delay of six minutes between the start of detector acquisition and the start of gradient feed in a liquid chromatography system. In this case, the first peaks 23 and 24 in the peak sequence of the complete UV chromatogram of cytochrome c may not be included in the detection window.

[0391] Fig. 7G represents a UV chromatogram of cytochrome c, measured with a delay of seven minutes between the start of detector acquisition and the start of gradient feed in a liquid chromatography system. In this case, the first peaks 23, 24, 25, and 26 in the peak sequence of the complete UV chromatogram of cytochrome c may not be included in the detection window.

[0392] If, all things considered, the time difference between the start of detector acquisition and the start of gradient injection is increased even further, it can happen that the first part of the eluting compounds is increasingly missing in the resulting chromatograms, as in Fig. 7F and Fig. 7G illustrated.

[0393] Overall, this shows that a suitable delay time t VerzIdeally, it should be chosen so that all peaks relevant for sample analysis are included. In the example shown, delay times t would be Verz of 2, 3 and 4 minutes (see Fig. 7C), D), E)) suitable to include all peaks in the chromatogram, and it is understood that suitable delay times can be found either by the user or by a software-controlled approach.

[0394] It is understood that embodiments of the approach presented here can make it possible to shorten the period in which no compounds can be eluted from a separation column due to a lack of elution solvents (see, for example, the hatched areas in Fig. 7) This may reduce the cycle time and thus increase throughput. Additionally, storage space can be saved, as no detector data is recorded during periods when no data relevant for analysis is present.

[0395] Fig. Figure 8 presents, as an example, preferred embodiments of a liquid chromatography system that uses a double-tube electrospray source and adopts four configurations according to embodiments of the present invention.

[0396] Configuration I, II, III, IV of Fig. 8 may correspond at least partially to features of, for example, the embodiments of one of the preceding figures.

[0397] The liquid chromatography system can include a double-tube electrospray source 39. The double-tube electrospray source 39 can, for example, replace the post-column switching valve 7 of the embodiments of Fig. 2, Fig. 3, Fig. 4 and / or Fig. 5 can be used. The liquid chromatography system can include a detector 22, which may be a mass spectrometry detector.

[0398] A double-tube electrospray source 39 can make it possible to selectively introduce fluid from one of the separation columns 5, 8 into the detector 22, while, for example, the other separation column 8, 5 is connected to the disposal (not shown).

[0399] In the Fig. In the embodiment shown in Figure 8, the first separation column 8 and the second separation column 5 are not contained in the column chamber 2. Instead, they can be contained in a column heater outside the column chamber 2.

[0400] In this embodiment, a detector 22 is also provided, which can be a mass spectrometer (MS) 22. The first separation column 8 and the second separation column 5 can be arranged close to the detector 22. Each of the columns 5, 8 can include an outlet. The outlet of the first column 8 can be connected to a first emitter, and the outlet of the second column 5 can be connected to a second emitter. The emitters are configured to spray directly into the MS 22. In general, the system is configured to selectively apply a high voltage to one of the emitters. Thus, only the liquid that arrives at the emitter to which the high voltage is applied is sprayed into the detector chamber. This functionality is described in Fig. 8 is represented by element 39. The selective application of the high voltage thus practically functions as a valve, since only the liquid at the emitter where the high voltage is applied is sprayed to the detector. In configurations I and II, the emitter connected to the first separation column 8 is supplied with high voltage, so that liquid in this branch is fed to the MS 22, while in configurations III and IV, the emitter connected to the second separation column 5 is supplied with high voltage, so that liquid in this branch is fed to the MS 22. Overall, this defines two different "tubes" that can be "connected" to the MS 22 by applying the high voltage, which is why this system can also be called a double-tube electrospray system.

[0401] As discussed, columns 5 and 8 can be located outside the column chamber and generally near the MS detector 22. Thus, the emitter at which the electrospray is generated is located directly at the column outlet. This spray is advantageously located in close proximity to an inlet of the MS 22 to facilitate the transfer of the generated charged species into the MS 22.

[0402] In general, this can be in Fig. The liquid chromatography system shown in Figure 8 is configured so that a high voltage is applied to only one tube at a time for electrospray ionization, i.e., either the first or the second tube. In other words, only one emitter may spray into detector 22 at a time. For example, the first tube can be subjected to a high voltage, and the first emitter of the first tube can therefore spray into detector 22, while the contents of the second tube can evaporate as they pass through the second tube or be directed to a disposal point; in both cases, one tube or the respective separation column is referred to as being fluidically connected to the disposal point. Conversely, the second tube can be subjected to a high voltage, and the second emitter of the second tube can therefore spray into detector 22, while the contents of the first tube can evaporate as they pass through the first tube or be directed to a disposal point.The first pipe is fluidically connected to the disposal system.

[0403] By alternately switching the high voltage to which the first tube and the second tube are exposed, the double-tube electro-spray source 39 can at least partially fulfill a similar purpose to the one described in Fig. The post-column switching valve 7 is shown in Figures 2 to 5. The use of the double-tube electrospray source 39 is particularly advantageous when, for example, the flow rates determined by a pump for liquid chromatography are less than 1 µl / min, as in applications in nanoflow liquid chromatography-mass spectrometry. The use of the double-tube electrospray source 39 can have the advantage that the volume of the fluid connection between at least one separation column and the detector in a liquid chromatography system can be minimized. This can lead to lower dispersion and a lower gradient delay, resulting in improved chromatographic performance with regard to, but not limited to, peak resolution and / or throughput.

[0404] In one embodiment of Fig. 8. In the first configuration I, the first tube can be subjected to a high voltage, and the first emitter of the first tube can therefore be enabled to spray into the detector 22 in the first configuration I. In one embodiment of Fig. 8. In the second configuration II, the first tube can be subjected to a high voltage, and the first emitter of the first tube can therefore be enabled to spray into the detector 22 in the second configuration II. In one embodiment of Fig. 8. In the third configuration III, the second tube can be subjected to a high voltage, and the second emitter of the second tube can therefore be enabled to spray into the detector 22 in the third configuration III. In one embodiment of Fig. 8 the second tube in the fourth configuration IV can be subjected to a high voltage and the second emitter of the second tube can therefore be enabled to spray into the detector 22 in the fourth configuration IV.

[0405] It is therefore generally understood that the in Fig. 8 first configuration shown I functionally of the in Fig. This corresponds to configuration I as shown in Figure 2. In this configuration, the separation pump 1 is connected to the first separation column 8 and the high voltage is applied to the first tube, so that the first emitter of the first tube sprays into the detector 22 (which functionally corresponds to connecting the first separation column 8 to the detector).

[0406] Furthermore, configuration II corresponds to Fig. 8 in general the in Fig. 3 shown configuration II. In this configuration, the processing pump 12 is fluidically connected to the first separation column 8 and the high voltage is supplied to the first tube, so that the first emitter of the first tube sprays into the detector 22.

[0407] It goes without saying that the in Fig. Configurations III and IV, as shown in section 8, generally correspond to those described in the... Fig. Configurations III and IV shown in 4 and 5, respectively.

[0408] Experts will therefore understand that the advantages described above for the system with a post-column switching valve 7 also apply when using the system of Fig. 8 can be achieved with a double-tube electrospray source.

[0409] In this respect, it is also understandable that a control unit 42, as in Fig. 2 to 5 are shown, usually also in the system of Fig. 8 is present, in Fig.However, number 8 has been omitted for the sake of simplicity.

[0410] Whenever a relative term such as "approximately," "significantly," "essentially," or "about" is used in this description, it should be interpreted as including the exact term. That is, for example, "essentially exactly" should also be interpreted as including "(exactly) exactly."

[0411] Whenever steps are mentioned in the preceding or attached claims, it should be noted that the order in which the steps are listed in this text may be arbitrary. That is to say, unless otherwise specified or it is clear to those skilled in the art, the order in which the steps are listed may be random. Thus, if this document states, for example, that a method comprises steps (A) and (B), this does not necessarily mean that step (A) precedes step (B), but it is also possible that step (A) is carried out (at least partially) simultaneously with step (B), or that step (B) precedes step (A). Moreover, if it is stated that one step (X) precedes another step (Z), this does not imply that no step takes place between (X) and (Z).This means that step (X), which precedes step (Z), includes the situation where step (X) is executed directly before step (Z), but also the situation where (X) is executed before one or more steps (Y1), ..., followed by step (Z). Similar considerations apply when expressions like "after" or "before" are used. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 2 449 372 B1

[0006] US 9,694,301 B2

[0007] EP 0 403 680 B1

[0008] EP 0 577 033 A1

[0009] US 10,722,816 B2

[0010] EP 1 342 202 A1

[0011] US 9,442,098 B2

[0012] US 10,775,355 B2

[0013] US 2018 / 0229152 A1

[0014] DE 10 2019 111783 A1

[0150]

Claims

[1] A method carried out in a liquid chromatography system, the method comprising: in a first configuration (I) in which a first separation column is fluidically connected to a separation pump and a detector, directing a flow from the first separation column to the detector by means of the separation pump in the first configuration (I), and Switching the liquid chromatography system from the first configuration (I) to a second configuration (II), wherein the first separation column is fluidically connected to a second pump and the detector, and directing a flow from the first separation column to the detector by means of the second pump in the second configuration (II). [2] Method according to claim 1, wherein in the first configuration (I) a second separation column is fluidically connected to the second pump and a disposal system, wherein the method further comprises directing a flow from the second separation column to disposal by means of the second pump in the first configuration (I), wherein in the second configuration (II) the second separation column is fluidically connected to the separation pump and the disposal, wherein the method in the second configuration (II) further comprises directing a flow from the second separation column to the disposal by means of the separation pump. [3] Method according to any one of the preceding claims, wherein the liquid chromatography system at a first switching time (T u ) switches from the first configuration (I) to the second configuration (II), wherein the method comprises switching the liquid chromatography system from the second configuration (II) to a third configuration (III), wherein the first separation column is fluidically connected to the second pump and a disposal system, wherein the method further comprises directing a flow from the first separation column to disposal by means of the second pump in the third configuration (III), wherein the liquid chromatography system at a second switching time (T III ) switches from the second configuration (II) to the third configuration, and where the second switching time (T III ) after the first switching time (T II ) lies. [4] Method according to claim 3, wherein the method comprises switching the liquid chromatography system from the third configuration (III) to a fourth configuration (IV), wherein the first separation column is fluidically connected to the separation pump and a disposal system, wherein the process further comprises directing a flow from the first separation column to disposal by means of the separation pump in the fourth configuration (IV), and wherein the liquid chromatography system at a third switching time (T IV ) switches from the third configuration (III) to the fourth configuration (IV), with the third switching time (T IV ) after the second switching time (T III ) lies. [5] Method according to claim 4, wherein in the fourth configuration (IV) the second separation column is fluidically connected to the second pump and the detector, and wherein the method in the fourth configuration (IV) further comprises directing a flow from the second separation column to the detector by means of the second pump. [6] Method according to claim 4 or claim 5, if dependent on claim 4, where the liquid chromatography system reaches a fourth switching time (T I) is switched from the fourth configuration (IV) back to the first configuration (I), thereby forming a cyclic process and thereby ending a previous cycle and starting a subsequent cycle, where the fourth switching point (T I ) after the third switching point (T IV ) lies, where the subsequent cycle follows the same temporal sequence, so that the times T II ', T III ', T IV ', T I ' of the following cycle at the respective time points T II , T III , T IV , T I correspond to the previous cycle. [7] Method according to claim 6, where a time difference t Verz between the second switching time (T III ) and the first switching time (T II ) on a volume V5 of the second separation column, on a volume V verbof fluid connections connected to the second separation column and based on a flow rate F of the separation pump, where a time difference t Verz ' between the fourth switching point (T I ) and the third switching point (T IV ) on a volume V8' of the first separation column, on a volume V verb ' of fluid connections connected to the first separation column, and based on a flow rate F of the separation pump. [8] Method according to claim 6 or 7, if dependent on claim 6, wherein the liquid chromatography system includes a pre-column switching valve, wherein the liquid chromatography system includes a post-column switching valve, wherein the method involves switching the liquid chromatography system via the pre-column switching valve from the first configuration (I) to the second configuration (II) at the first switching time T II includes wherein the method involves switching the liquid chromatography system via the pre-column switching valve from the third configuration (III) to the fourth configuration (IV) at the third switching time T IV The method comprises switching the liquid chromatography system via the post-column switching valve from the second configuration (II) to the third configuration (III) at the second switching time T. III includes wherein the method involves switching the liquid chromatography system via the post-column switching valve from the fourth configuration (IV) to the first configuration (I) at the fourth switching time T I includes. [9] Method according to claim 7 or 8, if dependent on claim 7, the procedure involves the use of an optimization procedure to optimize the time difference t Verz and / or the time difference t Verz ' includes, the procedure includes, at least in part, the use of a user interface in the steps of the optimization procedure. [10] Liquid chromatography system, the system comprising: a first separation column, a separation pump, and a detector wherein the first separation column is configured to be fluidically connected to the separation pump and the detector in a first configuration (I), wherein the system is configured to direct a flow from the first separation column to the detector by means of the separation pump in the first configuration (I), and where the system is configured to switch from the first configuration (I) to a second configuration (II), wherein the first separation column is configured to be fluidically connected to the second pump and detector in the second configuration (II), and the system is configured to direct a flow from the first separation column to the detector in the second configuration (II) using the second pump. [11] System according to claim 10, wherein the system further comprises: a second separating column, and a disposal, wherein the second separation column is configured to be fluidically connected to the second pump and to the disposal in the first configuration (I), the system is configured to direct a flow from the second separation column to disposal using the second pump in the first configuration (I). [12] System according to claim 10 or claim 11, where the system is configured to start the system at a first switching time (T II ) to switch from the first configuration (I) to the second configuration (II), wherein the system is configured to switch from the second configuration (II) to a third configuration (III), wherein the first separation column is configured to be fluidically connected to the second pump and a disposal, and wherein the system is configured to direct a flow from the first separation column to the disposal in the third configuration (III) by means of the second pump, where the system is configured to switch to a second switching time (T III ) to switch from the second configuration (II) to the third configuration, where the second switching time (T III ) after the first switching time (T II ) lies. [13] System according to claim 12, wherein the system is configured to switch from the third configuration (III) to a fourth configuration (IV), wherein the first separation column is fluidically connected to the separation pump and a disposal, and wherein the system is configured to direct a flow from the first separation column to the disposal in the fourth configuration (IV) by means of the separation pump. [14] System according to claim 13, wherein in the fourth configuration (IV) the second separation column is fluidically connected to the second pump and the detector and wherein the system is configured to direct a flow from the second separation column to the detector in the fourth configuration (IV) by means of the second pump. [15] System according to claim 13 or 14, if dependent on claim 13, where the system is configured to switch at a fourth switching time (T I) to switch from the fourth configuration (IV) back to the first configuration (I), thereby forming a cyclic process and thereby ending a previous cycle and starting a subsequent cycle, where the fourth switching point (T I ) after the third switching point (T IV ) lies and where a time difference t Verz ' between the fourth switching point (T I ) and the third switching point (T IV ) on a volume V8' of the first separation column, on a volume V verb ' of fluid connections connected to the first separation column, and based on a flow rate F of the separation pump. [16] System according to claim 15, where a time difference t Verz between the second switching time (T III ) and the first switching time (T II ) on a volume V5 of the second separation column, on a volume V verbof fluid connections connected to the second separation column and based on a flow rate F of the separation pump, where a time difference t Verz ' between the fourth switching point (T I ) and the third switching point (T IV ) on a volume V8' of the first separation column, on a volume V verb ' of fluid connections connected to the first separation column, and based on a flow rate F of the separation pump. [17] System according to any one of claims 10 to 16, wherein the liquid chromatography system includes a pre-column switching valve, wherein the upstream column switching valve comprises a multitude of ports and a multitude of connecting elements for interchangeably connecting the ports, where a connection of the pre-column switching valve to the separation pump is fluidically connected, a connection of the pre-column switching valve to the second pump is fluidically connected, a connection of the pre-column switching valve is fluidically connected to the first separation column, The connection of the pre-column switching valve is fluidically connected to the second separation column. [18] System according to claim 16 or 17, if dependent on claim 16, where the system is configured to use an optimization procedure to determine the time difference t Verz and / or the time difference t Verz ' to optimize. [19] Computer-readable medium comprising instructions which, when executed by a processor, cause the processor to control a liquid chromatography system to perform the method according to any one of claims 1 to 9.

Images