Methods and systems for operating an open port interface

Abstract

Methods and systems for operating an OPI of a sample analysis system, the OPI having a transport liquid conduit and a sample removal conduit and being configured to flow a transport liquid therethrough to a capture region, the method including introducing the OPI at a liquid sample in a sample reservoir while supplying the transport liquid at a first flow rate to the capture region, aspirating a first amount of the liquid sample through the removal conduit via the transport liquid flowing at the first flow rate, switching a flow rate of the transport liquid flowing through the OPI to a second flow rate when a first condition is met, the second flow rate being different from the first flow rate, and aspirating a second amount of the liquid sample through the removal conduit via the transport liquid flowing at the second flow rate. Fast flow rate switching is enabled by a transport liquid flow control apparatus comprising a selectable valve having a pair of valve outlets coupled to different flow paths having different flow resistances.

Description

[0001] METHODS AND SYSTEMS FOR OPERATING AN OPEN PORT INTERFACE

[0002] CROSS-REFERENCE TO RELATED APPLICATION

[0003]

[0001] This application is being filed as a PCT International Patent Application that claims priority to and the benefit of U.S. Provisional Application No. 63 / 516,715, filed on July 31, 2023, the disclosure of which is hereby incorporated by reference in its entirety.

[0004] BACKGROUND

[0005]

[0002] Open port interfaces (OPI) offer the control of a ratio of transport flow delivery into a port with respect to the port evacuation rate. A pump supplying transport flow liquid to the OPI is typically operated at a constant drive and flow pressure mode. Switching between various flow rates at the OPI may provide advantages. However, switching between flow pressure modes by using a pump is typically challenging due to inertia and delays inherent to the operation of the pump.

[0006] SUMMARY

[0007]

[0003] In one aspect of the present disclosure, method of operating an open port interface (OPI) of a sample analysis system, the OPI including a transport liquid conduit and a sample removal conduit and being configured to flow a transport liquid therethrough from the transport liquid conduit to a capture region of the OPI to the sample removal conduit, the method including introducing the OPI at a liquid sample in a sample reservoir while supplying the transport liquid at a first flow rate to the capture region, aspirating a first amount of the liquid sample through the removal conduit via the transport liquid flowing at the first flow rate, and switching a flow rate of the transport liquid flowing through the OPI from the first flow rate to a second flow rate when a first condition is met, the second flow rate being different from the first flow rate.

[0008]

[0004] In an example of the above aspect, the method further includes aspirating a second amount of the liquid sample through the removal conduit via the transport liquid flowing at the second flow rate. In a further example, the second flow rate is greater than the first flow rate. For example, supplying the first flow rate includes supplying a flow rate in a range of 0% to 60% of a balanced flow rate. In another example, switching the flow rate of the transport liquid to the second flow rate includes supplying a flow rate in a range of 40% to 110% of a balanced flow rate. In a further example, the first condition includes a first period of time before a tip of the OPI touches the liquid sample in the sample reservoir. For example, the first period of time includes a period of time in a range of 0.001 seconds to 20 seconds. In a further example, the first condition includes a time of contact between a tip of the OPI and the sample in the sample reservoir. In another example, the time of contact between the tip of the OPI and the sample in the sample reservoir is in a range of 0.001 second and 20 seconds. In a further example, the first condition includes a second period of time after a tip of the OPI touches the sample in the sample reservoir. In yet another example, the second period of time includes a period of time in a range of 0.001 seconds to 20 seconds.

[0009]

[0005] In an additional example of the above aspect, switching the flow rate of the transport liquid to the second flow rate is performed within a third period of time. For example, the third period of time is less than 500 ms. In another example, the third period of time is in a range of 10 ms to 500 ms. In a further example, one of aspirating the first amount of the liquid sample and aspirating the second amount of the liquid sample through the removal conduit includes aspirating the first or second amount of the liquid sample for a fourth period of time. For example, the fourth period of time includes a period of time in a range of about 0.001 second to 20 seconds. In another example, the fourth period of time includes a period of time of about 3 seconds. In a further example, the method further includes extracting the OPI from the sample while supplying a third flow of the transport liquid to the OPI after the fourth period of time has elapsed.

[0010]

[0006] In another aspect of the present disclosure, a transport liquid flow control apparatus includes a selectable valve including a single valve inlet and a pair of valve outlets, an inlet conduit fluidly coupling a transport liquid reservoir to the single valve inlet, a first resistance flow path fluidly coupling a first valve outlet of the pair of valve outlets to the OPI, wherein the first resistance flow path has a first flow resistance, and a second resistance flow path fluidly coupling a second valve outlet of the pair of valve outlets to the OPI, wherein the second resistance flow path has a second flow resistance higher than the first flow resistance.

[0007] In an example of the above aspect, the first resistance flow path is configured to generate a liquid flow rate in a range of 0% - 60% of a balanced flow rate. In another example, the second resistance flow path is configured to generate a liquid flow rate in a range of 40% - 1000% of a balanced flow rate.

[0011]

[0008] In another aspect of the present disclosure, a sample analyzing system includes a sample reservoir, the above transport liquid flow control apparatus coupled to an OPI, the OPI including a transport liquid conduit and a sample removal conduit, a sample ionization device fluidly coupled to the OPI, a sample analysis device coupled to the sample ionization device, at least one controller operatively coupled to the sample reservoir, the transport liquid flow control apparatus, the sample ionization device and the sample analysis device, and a memory coupled to the at least one controller, the memory storing instructions that, when executed by the processor, perform a set of operations. For example, the set of operations includes introducing, via the at least one controller, the OPI at a liquid sample in the sample reservoir while supplying the transport liquid at a first flow rate to a capture region of the OPI, aspirating, via the transport liquid flow control apparatus, a first amount of the liquid sample through the removal conduit via the transport liquid flowing at the first flow rate, and switching, via the transport liquid flow control apparatus, a flow rate of the transport liquid flowing through the OPI from the first flow rate to a second flow rate when a first condition is met, the second flow rate being different from the first flow rate.

[0012]

[0009] In another example, the set of operations further includes aspirating, via the transport liquid flow control apparatus, a second amount of the liquid sample through the removal conduit via the transport liquid flowing at the second flow rate. In another example, the set of operations includes supplying the transport liquid at the first flow rate by supplying the transport liquid at a flow rate in a range of 0% to 60% of a balanced flow rate. In an example, the set of operations includes switching the flow rate of the transport liquid flowing through the OPI to the second flow rate by supplying a flow rate of the transport liquid in a range of 40% to 110% of a balanced flow rate. In a further example, the first condition includes one of a first period of time before a tip of the OPI touches the liquid sample in the sample reservoir, a time of contact between a tip of the OPI and the liquid sample in the sample reservoir, and a second period of time after a tip of the OPI touches the liquid sample in the sample reservoir.

[0010] In an additional example, the set of instructions further includes performing switching the flow rate of the transport liquid flowing through the OPI to the second flow rate within a third period of time. For example, the third period of time is less than 500 ms. In another example, the third period of time is in a range of 10 ms to 500 ms. In a further example, the set of instructions includes aspirating the first amount of the liquid sample or the second amount of the liquid sample through the removal conduit by aspirating the first or second amount of the liquid sample for a fourth period of time. For example, the fourth period of time includes a period of time in a range of 0.01 second to 20 seconds. In a further example, the fourth period of time includes a period of time of about 3 seconds. In yet another example, the set of instructions further includes extracting the OPI from the liquid sample while supplying a third flow of the transport liquid to the capture region of the OPI after the fourth period of time has elapsed. In a further example, the sample reservoir is one of a plurality of wells in a well plate, and the sample is in one of the plurality of wells. In yet a further example, the sample analysis device includes at least one of a differential mobility spectrometer (DMS), a mass spectrometer (MS or MS / MS), and a DMS / MS. In another example, the sample ionization device includes one of a DESI device, a MALDI device, a LAP- MALDI device, a rapid-fire mass spectrometer, a pneumatic ESI device, an atmospheric pressure chemical ionization (APCI) device, and an El device.

[0013]

[0011] The details of one or more techniques are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of these techniques is apparent from the description, drawings, and claims.

[0014] BRIEF DESCRIPTION OF THE DRAWINGS

[0015]

[0012] FIG. 1 is a schematic diagram illustrating an example sample aspiration system combined with a mass analysis system, in accordance with various aspects and examples of the present disclosure.

[0016]

[0013] FIG. 2 is a schematic diagram illustrating another example mass analysis system in accordance with various aspects and examples of the present disclosure.

[0014] FIGS. 3A-3C depict partial cross-sectional views of a sample aliquot introduced to an OPI in a liquid-to-liquid sampling operation.

[0017]

[0015] FIGS. 4A-4C are illustrations of mass spectra for various flow rates, in accordance with various examples of the present disclosure.

[0016] FIG. 5 is an illustration of a flow control device for an OPI, in accordance with various examples of the present disclosure.

[0018]

[0017] FIGS. 6A-6C illustrate various flow modes for an OPI, in accordance with various examples of the disclosure.

[0019]

[0018] FIGS. 7A and 7B are flow charts illustrating methods for operating an OPI, in accordance with various examples of the disclosure.

[0020]

[0019] FIG. 8 is a schematic diagram illustrating one particular example of the computing device in accordance with various aspects and examples of the present disclosure.

[0021]

[0020] Before one or more examples of the present teachings are described in detail, one skilled in the art will appreciate that the present teachings are not limited in their application to the details of construction, the arrangements of components, and the arrangement of steps set forth in the following detailed description or illustrated in the drawings. Also, it is to be understood that the terminology used herein is for the purpose of description and should not be regarded as limiting.

[0022] DETAILED DESCRIPTION

[0023] Selected definitions

[0024]

[0021] For the purposes of interpreting this specification, the following definitions will apply and whenever appropriate, terms used in the singular will also include the plural and vice versa. The definitions set forth below shall supersede any conflicting definitions in any documents incorporated herein by reference.

[0025]

[0022] As used herein, the singular forms “a,” “an,” and “the,” include both singular and plural referents unless the context clearly dictates otherwise.

[0026]

[0023] The terms “comprising,” “comprises,” and “comprised of’ as used herein are synonymous with “including,” “includes,” or “containing,” “contains,” and are inclusive or open-ended and do not exclude additional, non-recited members, elements, or method steps. It is appreciated that the terms “comprising,” “comprises,” and “comprised of’ as used herein comprise the terms “consisting of,” “consists,” and “consists of.”

[0027]

[0024] The recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within the respective ranges, as well as the recited endpoints.

[0028]

[0025] Whereas the terms “one or more” or “at least one,” such as one or more or at least one member(s) of a group of members, is clear per se, by means of further exemplification, the term encompasses inter alia a reference to any one of said members, or to any two or more of said members, such as, e.g., any >3, >4, >5, >6, or >7, etc. of said members, and up to all said members.

[0029]

[0026] Unless otherwise defined, all terms used in the present disclosure, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present disclosure.

[0027] As used herein, “intensity” refers to the height of, or area under, a mass spectrometry (MS) peak. For example, the peak can be output data from a measurement occurring in a mass spectrometer (e.g., as a mass-to-charge ratio (m / z)). The charge “z” represents a charge state of an isotope cluster. In accordance with some examples of the present disclosure, intensity information can be presented as a maximum height of the summary peak or a maximum area under the summary peak representing a m / z value. The height or area of the summary peak representing the m / z values may be monitored over time for change.

[0030]

[0028] In the following passages, different aspects of the present disclosure are defined in more detail. Each aspect so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary.

[0031]

[0029] Reference throughout this specification to “one example” or “an example” means that a particular feature, structure, or characteristic described in connection with the example is included in at least one example of the present disclosure. Thus, appearances of the phrases “in one example” or “in an example” in various places throughout this specification are not necessarily all referring to the same example, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more examples. Furthermore, while some examples described herein include some, but not other features included in other examples, combinations of features of different examples are meant to be within the scope of the disclosure, and form different examples, as would be understood by those in the art. For example, in the appended claims, any of the claimed examples can be used in any combination.

[0032]

[0030] In the present disclosure, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration only of specific examples in which the present disclosure may be practiced. It is to be understood that other examples may be utilized, and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims.

[0033] Ionization devices

[0034]

[0031] Although the sample ionization process is described above in the context of mass spectrometry using ESI, other techniques of generating ionized samples may be used according to various examples of this disclosure. For example, ionized samples may be generated by DESI, which is a combination of ESI and desorption ionization (DI) methods. In DESI, ionization takes place by directing an electrically charged mist to the sample surface that is a few millimeters away. The electrospray mist is pneumatically directed at the sample, thus forming splashed droplets that carry desorbed, ionized analytes. After ionization, the ions travel through air into the atmospheric pressure interface which is connected to the mass spectrometer.

[0035]

[0032] Another ionization technique may include MALDI, which is an ionization technique that uses a laser energy absorbing matrix to create ions from large molecules with minimal fragmentation. In MALDI, a laser is fired at the matrix crystals in the dried-droplet spot. The matrix absorbs the laser energy; the matrix is desorbed and ionized (by addition of a proton) by this event. The hot plume produced during ablation contains many species: neutral and ionized matrix molecules, protonated and deprotonated matrix molecules, matrix clusters and nanodroplets.

[0036]

[0033] Other ionization techniques may include rapid-fire mass spectrometry, LAP- MALDI, pneumatic ESI (which generates ions for mass spectrometry using electrospray by applying a high voltage to a liquid to produce an aerosol), and EL El may also be referred to as electron impact ionization or electron bombardment ionization and is an ionization method in which energetic electrons interact with solid or gas phase atoms or molecules to produce ions. Any of the above techniques, as well as others that can perform sample ionization, may be used in examples of this disclosure. Other ionization techniques may include atmospheric pressure chemical ionization, APCI or atmospheric pressure photon ionization, APPI.

[0037] Open Port Interface

[0038]

[0034] An open port interface (OPI) allows the sampling of material by direct liquid extraction from a liquid source such as, e.g., a liquid reservoir, by physical transport of liquids to a sampling port. The material, once in the sampling port, is dissolved or diluted in the solvent system and delivered to the atmospheric pressure liquid ionization source of a mass spectrometer. Alternatively, the material is collected for other subsequent analyses. OPI ports are relatively new sampling devices that provide means of introducing a sample to, e.g., a mass spectrometer. An OPI port offers means of sample introduction into the transport stream at atmospheric pressure, a significant difference from more conventional introduction into a pressurized transport stream via a high-pressure valve. Typically, the OPI has been used as a surface sampler or to capture a defined droplet of a sample liquid. Another use of the OPI utilizes the probe to aspirate sample liquid from a surface or by direct immersion of the tip into the sample vial or by elution of a sample adsorbed on a solid phase target surface.

[0039]

[0035] Aspiration of sample through an OPI may lead to peak shape limitations in width, shape and sample transit time. Examples of the current disclosure reduce or eliminate these limitations. Current approaches to address this issue are based on direct control of the transport liquid pump such as, e.g., a positive displacement pump, and the pumping speed thereof. Alternatively, pump throttling is used in more large scale or industrial applications for flow control. However, both approaches typically result in slow control and slow response, and in the case of pump throttling, is more difficult to implement. Because neither approach uses a constant drive pressure for pump control, the drive pressures associated with the flow rate change slows down the process as the entire flow path may act as a pressure reservoir that needs to be charged and discharged to the new pressure level before a new, e.g., higher or lower, constant flow may be achieved. As a result, switching between a higher pressure and a lower pressure takes a too great amount of time to allow for flexible switching between different levels transport flows.

[0040]

[0036] Transport flow slowdown and stop were used in the past to enhance elution of adsorbed sample from solid phase surface targets as part of OPI. Examples of the current disclosure use transport flowrate variation to achieve better sampling efficiency by increasing the volume of the aspirated liquid sample while avoiding or reducing sample interaction with solid surfaces. The sample remains in liquid form and is not desorbed from a solid phase target surface. The transport flow variation of the current disclosure also improves detection, provides better control of transit time through the transport flow path, and an improved wash out of chemical memory effects.

[0041]

[0037] Examples of the present disclosure generally relate to providing fast and efficient aspiration sampling with an OPI probe for various applications such as, e.g., Affinity Selection - Mass Spectrometry (AS-MS), among other applications. Aspiration sampling with an OPI probe may enable high throughput capabilities while achieving increased or maximum sensitivity. The transport liquid flow that carries the aspirated sample to the ion source is rapidly switched from a flow regime that favors sampling to a higher flow regime that enhances transport and wash out of the transport liquid conduit. Detectability and throughput of the resulting measurement signal are improved as a result of this ability to rapidly switch between the flow regimes.

[0042]

[0038] In various examples, a pump supplying transport flow liquid to the OPI is operated at a constant pressure mode. The flow path of the transport flow liquid is split into two branches, each path having a different flow resistance. The flow paths are then merged together just before reaching the OPI port. Each of the two flow resistance paths is set or selected in order to deliver a specific flow rate, or flow rate range, into the OPI port. One flow rate may favor sample aspiration and sampling while the other flow rate may favor sample memory effects wash out. Both flow paths may be flooded and pressurized and the flow therethrough is selected by a fast valve that sends the flow of transport liquid through one or the other flow path supplying the OPI port. The advantage of having a pump deliver a constant pressure and relying on the fast valve to switch between flow paths is to the ability to achieve a much greater speed of flow rate change because the flow rate change is not the result of a change in pressure at the pump but the result of a diversion of the transport liquid and / or sample to one or the other flow path. The flow rate may typically change in 0.5 seconds or less, which is meaningful in terms of obtaining a high throughput sampling, and the combination of a fast-acting valve (< 0.1 sec) and constant pressure pumping mode can achieve this speed advantage.

[0043]

[0039] The OPI offers the ability to control the ratio of transport flow delivery into the port with respect to the evacuation rate of the transport flow delivery out of the port. The port is evacuated due to a pull generated by a rapidly expanding nebulizer gas over an end of the transport conduit, hence the pull can be controlled via the nebulizer gas flow. The transport flow is delivered to the port by a pump that controls the flow rate entering the port. Accordingly, the port may be made to operate in a “starved,” also referred to as over-pumped, flow condition where the transport flow entering the port is less, sometimes significantly less, than the transport flow evacuating from the port. The port can also be made to operate in a balanced, also referred to as closed, flow condition where the flow rate entering the port matches, or is substantially equal to, the evacuation flow rate. The port can also be made to operate in an overflow, also referred to as under-pumped, flow condition where more flow enters the port than is evacuated from the port. As further discussed below, balanced (closed) flow may be referred to as “cflow,” over-pumped or starved mode may be expressed as “flow < cflow,” and under-pumped mode or overflow mode may be expressed as “flow > cflow.”

[0040] The sampling method according to various examples includes flow rate switching by switching flow paths rather than controlling the turning on and off of the pump, which is typically a slow process given the response time and pressure accumulation of the pump. Instead, the pump operates at a constant drive pressure mode, but the flow path is altered from a high flow resistance flow path to a low flow resistance flow path for a period of time. Because the drive pressure remains constant, the low resistance flow path may result in an increase in flow rate, and the high resistance flow path may result in a decrease in flow rate. The switch between the two flow paths, or two branches of flow path, may be achieved by using, e.g., a fast-acting valve of low internal volume. As a result, an actual flow rate change occurring at, e.g., less than 500 msec, may be achieved. For example and as further discussed below, for the spectrum of a starved or over-pumped configuration, the peak shape of the resulting measured signal improves in terms of peak area, peak height, and peak width, as the transport flow is reduced to below 0.15cflow. This scenario maximizes the uptake rate of the sample, minimizes dilution, and maximizes transport rate of the sample. In examples, the uptake rate may be the difference between transport flow delivered to the port and the balanced flow cflow. For example, when the transport flow is 0.15cflow, then the uptake rate of 0.85cflow.

[0044]

[0041] FIG. 1 is a schematic view of an example system 100 combining an OPI sampling interface 104 and an ESI source 114. The system 100 may be a mass analysis instrument such as, e.g., a mass spectrometry device, for ionizing and mass analyzing analytes received within an open end of sampling OPI 104. Such a system 100 is described, for example, in U.S. Pat. No. 10,770,277, the disclosure of which is incorporated by reference herein in its entirety. Liquid samples are contained within individual wells 110 of a well plate 112, which may be moved via a moveable stage 134. Movement may be enabled via one or more motors or other actuators depicted generally at 132a. Such movement may include movement of the stage 134 and well plate 112 relative to and towards the OPI 104, so as to enable contact between the OPI 104 and the liquid samples in the various wells 110, as described in further detail below. Alternatively, or additionally, another set of motors / actuators 132b may move the OPI 104 relative to and towards the well plate 112. Accordingly, movement of the OPI 104 relative to the wells 110 may be achieved via movement of the OPI 104, movement of the well plate 112, or both.

[0045]

[0042] As shown in FIG. 1, the example system 100 generally includes the sampling OPI 104 in liquid communication with the ESI source 114 for discharging a liquid containing one or more sample analytes into an ionization chamber 118 via, e.g., electrospray electrode 116, and a mass analyzer detector, depicted generally at 120, in communication with the ionization chamber 118 for downstream processing and / or detection of ions generated by the ESI source 114. Due to the configuration of the nebulizer probe 138 and electrospray electrode 116 of the ESI source 114, samples ejected therefrom are in a nebulized plume that desolvates to the gas phase. A liquid handling system 122, e.g., including one or more pumps 124 and one or more transfer conduits 125, provides the flow of liquid from a solvent reservoir 126 to the sampling OPI 104 and from the sampling OPI 104 to the ESI source 114. The solvent reservoir 126 (e.g., containing a liquid and a desorption solvent, also referred to as transport liquid) can be liquidly coupled to the sampling OPI 104 via a supply conduit 127 through which the liquid can be delivered at a selected volumetric rate by the pump 124 such as, e.g., a reciprocating pump, a positive displacement pump such as a rotary, gear, plunger, piston, peristaltic, diaphragm pump, or other pump such as a gravity, impulse, pneumatic, electrokinetic, and centrifugal pump, all by way of non-limiting example. Further examples of sampling OPIs, including those that perform a washing function of the OPI between obtaining of samples from different wells, are described in more detail below.

[0046]

[0043] The flow of liquid sample into and out of the sampling OPI 104 occurs within a sample space accessible at the open end such that one or more sample aliquots from, e.g., one or more sample wells 110, can be introduced into the port inlet 128 at the OPI 104 tip and subsequently delivered to the ESI source 114, by being drawn first into a sample removal conduit 131 within the OPI 104. A controller 130 may be operatively coupled to the various components depicted herein. Controller 130 can be, but is not limited to, a microcontroller, a computer, a microprocessor, or any device capable of sending and receiving control signals and data. Wired or wireless connections between the controller 130 and the remaining elements of the system 100 are not depicted but would be apparent to a person of skill in the art.

[0044] Examples of the disclosure utilize OPI 104 to introduce sample aliquots to mass analysis system 120 via direct liquid-to-liquid contact. Direct liquid-to-liquid contact is different from adsorbed sample elution from a solid phase target surface, such as solid phase micro extraction (SPME) surface. That is, the OPI 104 containing transport liquid is placed in contact with a liquid sample, which pins an aliquot to the OPI inlet port 128. The OPI 104 acts as an atmospheric pressure injector with no moving parts that is capable of high throughput sample cadence with high degree of accuracy and reproducibility. This method enables delivery of sample aliquot volumes comparable to that of conventional high performance liquid chromatography (HPLC) injectors. Such a configuration offers ease of use, ease of implementation, and robustness. The OPI 104 described herein is also suitable for ESI, which requires liquid delivery of sample to an ESI probe, such as described in the context of FIG. 1. The OPI 104 also enables sampling larger volumes of liquid, typical to conventional chromatography workflows that seek to exploit the limit of detection range of modem MS.

[0047]

[0045] As shown in FIG. 1, the ESI source 114 can include a source 136 of pressurized gas (e.g. nitrogen, air, or a noble gas) that supplies a high velocity nebulizing gas flow to the nebulizer probe 138 that surrounds the outlet end of the electrospray electrode 116. As depicted, the electrospray electrode 116 protrudes from a distal end of the nebulizer probe 138. The pressured gas interacts with the liquid discharged from the electrospray electrode 116 to enhance the formation of the sample plume and the ion release within the plume for sampling by mass analyzer detector 120, e.g., via the interaction of the high-speed nebulizing flow and jet of liquid sample (e.g., analyte-solvent dilution). The liquid discharged may include discrete volumes of liquid samples LS received from each reservoir 110 of the well plate 112. The discrete volumes of liquid samples LS may be separated from each other by volumes of the solvent S (hence, as flow of the solvent moves the liquid samples LS from the OPI 104 to the ESI source 114, the solvent may also be referred to herein as a transport liquid). The nebulizer gas can be supplied at a variety of flow rates, for example, in a range from about 0.1 L / min to about 20 L / min, which can also be controlled under the influence of controller 130 (e.g., via opening and / or closing valve 140).

[0048]

[0046] It will be appreciated that the flow rate of the nebulizer gas can be adjusted (e.g., under the influence of controller 130) such that the flow rate of liquid within the sampling OPI 104 can be adjusted based, for example, on suction / aspiration force generated by the interaction of the nebulizer gas and the analyte-solvent dilution as it is being discharged from the electrospray electrode 116 (e.g., due to the Venturi effect). The ionization chamber 118 can be maintained at atmospheric pressure, though in some examples, the ionization chamber 118 can be evacuated to a pressure lower than atmospheric pressure.

[0049]

[0047] It will also be appreciated by a person skilled in the art and in light of the teachings herein that the mass analyzer detector 120 can have a variety of configurations. Generally, the mass analyzer detector 120 is configured to process (e.g., filter, sort, dissociate, detect, etc.) sample ions generated by the ESI source 114. By way of non-limiting example, the mass analyzer detector 120 can be a triple quadrupole mass spectrometer, or any other mass analyzer known in the art and modified in accordance with the teachings herein. Other non-limiting, exemplary mass spectrometer systems that can be modified in accordance with various aspects of the systems, devices, and methods disclosed herein can be found, for example, in an article entitled "Product ion scanning using a Q-q-Q linear ion trap (Q TRAP) mass spectrometer," authored by James W. Hager and J. C. Yves Le Blanc and published in Rapid Communications in Mass Spectrometry (2003; 17: 1056-1064); and U.S. Pat. No. 7,923,681, entitled "Collision Cell for Mass Spectrometer," the disclosures of which are hereby incorporated by reference herein in their entireties.

[0050]

[0048] Other configurations, including but not limited to those described herein and others known to those skilled in the art, can also be utilized in conjunction with the systems, devices, and methods disclosed herein. For instance, other suitable mass spectrometers include single quadrupole, triple quadrupole, ToF, trap, and hybrid analyzers. It will further be appreciated that any number of additional elements can be included in the system 100 including, for example, an ion mobility spectrometer (e.g., a differential mobility spectrometer) that is disposed between the ionization chamber 118 and the mass analyzer detector 120 and is configured to separate ions based on their mobility difference under high-field and low-field conditions. Additionally, it will be appreciated that the mass analyzer detector 120 can comprise a detector that can detect the ions that pass through the mass analyzer detector 120 and can, for example, supply a signal indicative of the number of ions per second that are detected. A sampling event includes the OPI inlet port such as, e.g., the port inlet 128 at the OPI 104 illustrated in FIG. 1, being momentarily immersed into a sample liquid in a reservoir such as a well 110, or alternatively touches the sample liquid surface, where the OPI inlet port 128 acts as the injector

[0051]

[0049] FIG. 2 is a schematic diagram illustrating another example mass analysis system in accordance with various aspects and examples of the present disclosure. In the illustrated examples, the system 10 can each include, in various combinations, pluralities of components, including some or all of a mass capture and analysis system 100 and a computing system 103. In some examples, the mass capture and analysis system 100 may be a mass analysis instrument 100. The mass capture and analysis system 100 may be a mass spectrometer system including a mass analyzer 120 for analyzing ions generated from ionization of a sample. The mass capture and analysis system 100 may include or be coupled to a capture device or probe 105 that captures the sample and provides the sample to other components of the mass capture and analysis system 100. In other examples, the capture probe 105 may be located externally from the mass analysis instrument 100.

[0052]

[0050] It will also be appreciated by a person skilled in the art and in light of the teachings herein that the mass analyzer 120 can have a variety of configurations. Generally, the mass analyzer 120 is configured to process (e.g., filter, sort, dissociate, detect, etc.) sample ions generated by the ion source 115. By way of non-limiting example, the mass analyzer 120 can be a triple quadrupole mass spectrometer, or any other mass analyzer known in the art and modified in accordance with the teachings herein. Other non-limiting, exemplary mass spectrometer systems that can be modified in accordance with various aspects of the systems, devices, and methods disclosed herein can be found, for example, in an article entitled “Product ion scanning using a Q-q-Q linear ion trap (Q TRAP) mass spectrometer” (James W. Hager and J. C. Yves Le Blanc; Rapid Communications in Mass Spectrometry; 2003; 17: 1056-1064); and U.S. Pat. No. 7,923,681, the disclosures of which are hereby incorporated by reference herein in their entireties.

[0053]

[0051] Other configurations, including but not limited to those described herein and others known to those skilled in the art, can also be utilized in conjunction with the systems, devices, and methods disclosed herein. For instance, other suitable mass spectrometers include single quadrupole, triple quadrupole, time-of-flight (ToF), trap, and hybrid analyzers. It will further be appreciated that any number of additional elements can be included in the system 100 including, for example, an ion mobility spectrometer (e.g., a differential mobility spectrometer) that is disposed between the ionization source 115 and the mass analyzer detector 120 and is configured to separate ions based on their mobility difference between in high-field and low-field).

[0054] Additionally, it is appreciated that the mass analyzer 120 can include a detector that can detect the ions that pass through the analyzer 120 and can, for example, supply a signal indicative of the number of ions per second that are detected.

[0055]

[0052] The system 10 may also include a sample source 70 and a sample handler 80. The sample source 70 and a sample handler 80 are operative to retrieve collections of samples from the sample source(s) and to deliver the retrieved collections to capture locations associated with sample capture probe 105. The systems may be operative to independently capture selected ones of the pluralities of samples at the capture locations from the pluralities of samples, to optionally dilute the samples and to transfer the captured samples to mass analysis instruments 100, 120 for mass analysis. In some examples, the sample source 70 may include a set of well plates in a storage housing and / or liquid for adding to well plates. The sample source 70 may include part of a liquid handling system that manipulates and / or injects liquid into the well plates. The sample handler 80 includes one or more electro-mechanical devices (e.g., robotics, conveyor belts, stages, etc.) that are capable of transferring the samples (e.g., well plates) from the sample source to other components of the system 10 and / or to other systems, such as the capture probe 105. As an example, the sample handler 80 may transfer a well plate to the ejector 90 which may be acoustic or pneumatic. In other examples, the system 10 does not include an ejector such as ejector 90 and an ejection controller such as ejection controller 92. More specifically, the sample handler 80 may transfer the well plate to a plate handler 95. With reference to FIG. 1, the plate handler 95 may be similar to the stage 134. In some examples, selected sample information (e.g. sample or compound ID, chemical structure of the target compound, or other sample information) may be obtained during sample handling through the use of sample controller 82 and / or the sample handler 80, and communicated to the computing system 103 or the data processing system 150 thereof.

[0056]

[0053] In an example, the plate handler 95 receives a well plate from the sample handler 80. The plate handler 95 transports the plate to a capture location that may be aligned with the capture probe 105. The plate handler 95 may include one or more electro-mechanical devices, such as a translation stage that translates the well plate in an x-y plane to align wells of the well plate with the capture probe 105.

[0054] The computing system 103 includes computing resources, components, and modules that are operative to perform various functions including but not limited to: communicating with other subsystems, receiving and transmitting electrical signals with other subsystems or components thereof, receiving, responding to, and executing user instructions, performing calculations, processing raw data received from mass analyzer, performing splitting data, performing sample-dataset correlation, generating and analyzing mass spectrometry data, identifying, annotating, and assigning MS peaks of mass spectra, extracting spectral features from mass spectra, conducting library search, identifying analytes, and outputting analytical report to end users.

[0057]

[0055] In some examples, the computing system 103 includes a computing device 200, a controller 135, and a data processing system 150. The computing device 200 may be in the form of electronic signal processors and operative to perform various computing functions, and may be similar to the computing device 800 discussed below with respect to FIG. 8. The controller 135 may be in the form of electronic signal processors and in electrical communication with other subsystems within the system 10. The controller 135 is further configured to coordinate some or all of the operations of the pluralities of the various components of the system 10. The data processing system 150 may include various components and modules operative to process mass spectrometry data and to provide real-time feedback to end users and other subsystems.

[0056] In operation, a sample delivery system (including sample source 70 and sample handler 80) can iteratively deliver independent samples from a plurality of samples (e.g., a sample from a well of a well plate 75) to the capture probe 105. The capture probe 105 can dilute and transport each such delivered sample to the ion source 115 disposed downstream of the capture probe 105 for ionizing the diluted sample. A mass analyzer 120 can receive generated ions from the ion source 115 for mass analysis. The mass analyzer 120 is operative to selectively separate ions of interest from generated ions received from the ion source 115 and to deliver the ions of interest to an ion detector that generates a mass spectrometer signal indicative of detected ions to the data processing system 150. In some aspects, the separate ions of interest may be indicated in an analysis instruction associated with that sample. In some aspects, the separate ions of interest may be indicated in an analysis instruction identified by an indicia physically associated with the plurality of samples.

[0058]

[0057] In some aspects, the system 10 may further include the generation, assignment, and use of identifiers associated with collections of samples and / or individual samples, and incorporation by one or more of components 70, 80, 95, 105, 100, etc. of identifier readers. For instance, an identifier associated with a well plate may be read or scanned by a machine reading device 65 as it leaves the sample source 70 and / or when the well plate is received by the stage 95. In such aspects, the identifiers) may be used by the system to associate a corresponding one or more sets of instructions for use by the mass analysis instrument 100, 120 when analyzing transported sample droplets 125. In some aspects, the identifier may include an indicia physically associated with the plurality of samples. In some aspects, the indicia may be readable by optical, electrical, magnetic, or other non-contact reading means. Indicia or identifiers in accordance with such aspects of the disclosure can include any characters, symbols, or other devices suitable for use in adequately identifying samples, sample collections, and / or handling or analysis instructions suitable for use in implementing the various aspects and examples of the present disclosure.

[0059]

[0058] The controller 135 may include, for example, an a Sciex OS computer available from Sciex, or other control component. The Sciex OS computer includes a control component 107 for the capture probe 105, represented for example by Sciex open port probe (OPP) (also referred to as an OPI) software, and a control component 137 for the mass analysis instrument 100. The mass analysis instrument 100 and capture probe controller 107 may be further in operative communication with X-Y Well Plate Stage 95 and plate handler controller 96, which may be, for example, an embedded computer or processor. For the purposes of this application, these distributed controller components may collectively be considered to be a system controller, and depending upon the configuration may be centralized, or distributed as is the case here. For instance, one of the controllers or controller components may send signals to the other controllers to control the respective devices.

[0060]

[0059] FIGS. 3A-3C illustrate partial cross-sectional views of a system 300 depicting a liquid sample introduced to an OPI 304 in a liquid-to-liquid sampling operation from a liquid sample source 306 such as, e.g., a well of a well plate, which includes a liquid sample 302. The OPI 304 includes housing 305 defining at a lower end thereof an inlet port 307. The housing 305 defines therein a transport liquid supply conduit 310, in which is disposed a sample removal conduit 308. The transport liquid (e.g., methanol), illustrated by arrows, is delivered via the transport liquid supply conduit 310 and forms a meniscus 312 proximate the inlet 307 of the OPI 304.

[0061] Thereafter, the transport liquid is aspirated into the sample removal conduit 308. The aspiration pressure draws the meniscus 312 into the sample removal conduit 308, and may deform the meniscus 312 into an overpumped condition, where the meniscus 312 is drawn towards the removal conduit 308.

[0062]

[0060] In FIG. 3B, the OPI 304 is moving in a first direction relative to the liquid sample source 306. This movement may be movement Mo of the OPI 304 towards the liquid sample source 306, or may be movement Ms of the liquid sample source 306 towards the OPI 304, or a combination of both resulting in the inlet port 307 contacting the liquid sample 302, as illustrated in FIG. 3B. After contact is established between the inlet port 307 and the liquid sample 302, as depicted in FIG. 3C, the contact between the inlet port 307 and the liquid sample 302 captures a sample aliquot 302a. The aliquot 302a is visible as the OPI 304 is moved in a second direction relative to the liquid sample source 306, e.g., away from the liquid sample source 306. As discussed herein, the relative movement may be movement of the OPI Mo away from the liquid sample source 306, movement of the sample source Ms away from the OPI 304, or a combination of both. Capturing the sample aliquot 302a at the inlet port 307 forms an air gap 314 between the aliquot 302a and the meniscus 312, as depicted in FIG. 3C. Over a brief time, however, due to contact between the transport liquid in the transport liquid supply conduit 310, the air gap 314 and the aliquot 302a are drawn toward the removal conduit 308 away from the inlet port 307. This effectively withdraws the air gap via removing, pumping, or dissolving the air within the combination of the aliquot 302a and the transport liquid being aspirated from the removal conduit 308, and repositions the meniscus 312 closer to the inlet port 307. For example, if the port 304 is kept inside sample liquid 302 for longer than 500msec, the sample may be aspirated at a flow rate that is the difference between the supplied transport flow rate and cflow.

[0061] FIGS. 4A-4C are illustrations of mass spectra obtained from sampling operations as discussed above with respect to FIGS. 3A-3C for various flow rates, in accordance with various examples of the present disclosure. FIG. 4A shows an example of peak shape evolution with increasing transport flow rate. For example, peak 410 represents a flow rate of 0.12cflow, e.g., a starved or over-pumped flow corresponding to 12% of a balanced flow, and shows the best peak for detection and quantitation compared to the other peak 420-460. Such a flow condition is depicted generally in FIG. 3A above. The best peak in this case is the peak with the highest signal or intensity. Peak 420 represents a flow of 0.23cflow, e.g., a starved flow corresponding to 23% of a balanced flow. Peak 430 represents a flow of 0.33cflow, e.g., a starved flow corresponding to 33% of a balanced flow. Peak 440 represents a flow of 0.48cflow, e.g., a flow corresponding to 48% of a balanced flow. Peak 450 represents a flow of 0.64cflow, e.g., a flow corresponding to 64% of a balanced flow. Peak 460 represents a flow of 0.79cflow, e.g., a flow corresponding to 79% of a balanced flow.

[0063]

[0062] From FIG. 4A, it is possible to determine that the intensity of the measured peak decreases as the flow rate increases. However, although peak 410, corresponding to a trace for the 0.12 cflow provides a high intensity peak, operating at flows at 0.12 cflow or below may have disadvantages because, e.g., the transport liquid is not effectively cleared from the OPI conduit, illustrated as 308 in FIGS. 3A-3C. At this severely starved, over-pumped, range of flow rates, the amount of transport liquid to be transferred to the OPI is small, and as a result the transport liquid travels along the OPI conduit as individual packets of liquid. The result of having individual packets of liquid travel along the OPI conduit to the mass analysis device is the generation of gaps in the resulting trace for periods of time as high as, e.g., tens of seconds due to the existence of air gaps in the flow, thus limiting the throughput of the device. Accordingly, the resulting trace may include a series of significant signal spikes separated by large air gaps, as illustrated in FIG. 4B further discussed below.

[0064]

[0063] In particular, in FIG. 4B, which illustrates a trace 400, showing peaks 410 and 415, which are part of the same measurement, that are separated by an air gap 412 therebetween. According to various examples, this limiting feature of the highly starved or over-pumped transport mode creates air gaps within the measurement trace that may be overcome or mitigated by introducing a fast and momentary increase in the transport flow rate to near, at, or above a balanced flow rate e.g., cflow. Such temporary increased flow rate may be synchronized with the sampling or aspiration event of the transport liquid within the OPI conduit. In an example, the temporary increase in the transport flow rate may reduce or eliminate the air gaps 412 between adjacent peaks 410 and 415, as illustrated in FIGS. 4B and 4C, and may thus push the tail peak, illustrated as peak 415 in FIG. 4B, closer to the main peak 410. As a result, the width of the resulting peak 425 may be slightly increased, and the peak area may also be increased, as further discussed below and illustrated in FIG. 4C.

[0065]

[0064] In FIG. 4C, which illustrates a trace 402, the left-hand side of the trace 402 illustrates a selected mass pair spectrum where, e.g., parent to fragment transition is monitored, obtained when the sampling operates at a starved or over-pumped flow and shows a main peak 410 and a secondary peak 415, the main peak 410 and the secondary peak 415 being separated by an air gap 412 of a given duration, e.g., a duration of about 7 seconds, while the width of the peak 410 is about 2 seconds. In examples, the flow of the trace constituted by peaks 410 and 415 may be about O.lOcflow, or 10% of a balanced flow. Accordingly, the distance 412 corresponds to the presence of an air gap within, e.g., the sample removal conduit 308 illustrated in FIGS. 3A-3C, the air gap being created by the fact that the sampling is in a starved mode where a too-small amount of transport fluid travels through the conduit 308 per unit of time. Accordingly, the air gap 412 creates a separation between the resulting detection signals expressed by peaks 410 and 415 separated by the gap 412.

[0066]

[0065] The right-hand side of FIG. 4C illustrates a single main peak 425 for a sampling configuration that is less transport flow starved than for the trace of peaks 410 and 415. For example, the sampling flow rate for the trace having peak 425 may correspond to a higher flow rate, such as, e.g., about cflow, or a balanced flow. In this case, the trace has a single peak 425 that is wider than peak 410 of the starved sampling example of peaks 410 and 415, and does not have a secondary peak separated by an air gap. In the example of peak 425, the width of the peak 425 is about 3.5 seconds, which is wider than the width of 2 seconds of peak 410. The absence of the air gap indicates that during sampling, the liquid sample such as, e.g., the liquid sample 302 illustrated in FIGS. 3A-3C, is terminated by the increased transport flow through the removal conduit 308 for a period of time following a starved configuration, and as a result no air gap or air bubble is present inside the removal conduit 308 which could create a gap such as gap 412.

[0067]

[0066] In order to obtain a higher quality peak such as peak 425, referring back to FIGS. 3A-3C, in various examples, the flow of the transport liquid is switched from a low, or starved, flow rate to a higher flow rate at or around the time the inlet port 307 touches the surface of the liquid sample 302. Accordingly, when the flow rate switches from low flow rate to higher flow rate, the presence of any air gaps in the removal conduit 308 is substantially eliminated or reduced, and a higher quality peak, i.e., a peak with no air gaps therebetween, such as peak 425 may be generated in the resulting trace. In other examples, the flow rate may be switched, as discussed above, from low flow rate to higher flow rate at or around the time the inlet port 307 touches the surface of the liquid sample 302, but may alternatively also be switched from a given flow rate to a lower flow rate, or from a low flow rate to a higher flow rate and then back to a low flow rate, also at or around the time the inlet port 307 touches the surface of the liquid sample 302. The process described above may be repeated as multiple sample reservoirs may be tested. In various examples, low transport flow may be used at or around sample acquisition at the inlet port 307, followed by a switch to high transport flow to terminate the liquid sample plug (LS) illustrated in FIG. 1. Such a termination improves signal peak shape, detectability and chemical memory clearance. Following the termination, the transport flow may be switched back to the low flow to prepare for the aspiration of the next sample from the next sample well (or alternatively from the same well). The process is repeated for the next sample and continues through the user supplied sample list. As discussed above, the sequence may also operate with high transport flow being switched to lower transport flow only for the sample aspiration event. Reduction of transport flow during the sample aspiration may increase the sample aspiration rate, and hence may increase the collected signal, for events longer than 500msec. The transport flow rate switch typically occurs at or around the time when the inlet port 307 reaches the sample liquid surface, but it may also happen before or after that, for signal (peak shape) control, as further discussed below.

[0068]

[0067] FIG. 5 is an illustration of a flow control device for an OPI, in accordance with various examples of the present disclosure. In order to switch from low flow rate to high flow rate, or vice versa, a flow control device 500 may be used. In examples, the flow control device 500 includes a pump 505 coupled to a liquid reservoir 510. The liquid reservoir 510 is representative of any liquid reservoir and may contain any liquid such as, e.g., a transport liquid or a liquid sample. Accordingly, the pump 505 delivers the liquid from the reservoir 510 via a conduit 520 to a valve 530 at a constant pressure. Upon receiving the liquid from the conduit 520, the valve 530 selects one of two flow paths at a valve connector 532, a low resistance flow path 534 or a high resistance flow path 536. The flow paths 534 and 536 may have, e.g., inner diameters of different sizes, different profiles or different geometries, which may create more or less resistance to the liquid flowing therethrough. For example, the inner diameter of the high resistance flow path 536 may be about 0.25 mm and may have a length of about 32 cm, resulting in a pressure drop thereacross of about 2.7 psi for a transport flow of about 600 pL / min of Methanol. The high and low resistance flow paths merge into a common channel to OPI 540. For example, the inner diameter of the OPI 540 may be about 0.51 mm and may have a length of about 50 cm, resulting in a pressure drop thereacross of about 0.3 psi for a transport flow of about 600 pL / min of Methanol. A pump operating at a constant pressure of about 3 psi (2.7 psi + 0.3 psi) may deliver about 600 pL / min of Methanol through the high resistance flow path. The inner diameter of the low resistance flow path 534 may be about 0.76 mm and may have a length of about 22 cm, resulting in a substantially negligible drop thereacross. Thus, for a pump operating at a constant pressure of about 3 psi, the flow rate through the low resistance flow path may be set by the common channel to OPI 540, resulting in about a ten times (lOx) greater flow rate than for the high resistance flow path.

[0069]

[0068] Due to the presence of the two flow paths 534 and 536 having different flow path resistances, the liquid may be delivered to the OPI 540 via one of the two flow paths 534 and 536, as desired. For example, if a low flow rate is desired, then the liquid may be diverted to the high resistance flow path 536, and if a higher flow rate is desired, then the liquid may be diverted to the low resistance flow path 534. With reference in parallel to FIGS. 3A-3C, the high resistance flow path 536 may be selected as the OPI 304 and the sample source 306 are coming in contact with each other thus increasing the liquid sample aspiration as discussed earlier. At about the time of contact between the inlet port 307 and the surface of the liquid sample 302, the valve 530 switches the path of the transport liquid from the high resistance flow path 536 to the low resistance flow path 534, thereby increasing the flow rate of the transport liquid, terminating the liquid sample (LS) aspiration with a transport liquid plug of solvent (S), arriving at the OPI 304 (or OPI 540 in FIG. 5). Accordingly, a higher quality trace having a peak, such as peak 425 illustrated in FIG. 4C, may be obtained.

[0070]

[0069] In various examples, the flow rate of the transport liquid and liquid sample may be switched back and forth between high flow rate and low flow rate via the valve 530 in order to obtain a higher quality peak, in order to wash out the conduit after a sampling operation, or in order to start a new sampling process. Using a liquid flow at a constant pressure may overcome the typically long lag time in the flow generator or pump 505 when switching from low pressure to high pressure or vice-versa. By keeping the pump 505 generating a constant pressure and by relying on switching between flow paths 534 and 536, the liquid sample flow rate switching time may be greatly reduced.

[0071]

[0070] FIGS. 6A-6C illustrate various flow modes for an OPI 600, in accordance with various examples of the disclosure. The illustrated flow modes include a starved mode (FIG. 6A), a balanced mode (FIG. 6B), and an overflow mode (FIG. 6C). The flow modes depicted in FIGS. 6A-6C are applicable to the technologies described herein. Each OPI 600 depicted in FIGS. 6A-6C includes an outer housing 652 that defines a transport liquid conduit 654 therein. FIG. 6A illustrates the starved mode, also referred to as over-pumped mode. Within the housing 652 is a removal conduit 656 out of which transport liquid and samples 662 are drawn to, e.g., an ESI and mass analysis device, as described elsewhere herein. The outer housing 652 also defines a tip or inlet port 658. In general, when operating in a starved mode as illustrated in FIG. 6A, the highly curved meniscus 660 of the transport liquid and sample 662 flowing within the OPI 600 is drawn towards the removal conduit 656 and away from the tip or inlet port 658. This highly curved meniscus 660 may be characterized by fairly low flow rates of transport liquid 662 adjacent to the edges of the tip or inlet port 658, and with higher flow rates of transport liquid 662 closer to the removal conduit 656. An inner diameter of the removal conduit 656 may be about 0.25 mm or 0.5 mm, and a length thereof may be about 50 cm. The low transport flow requiring only a small fraction (<25%) of the OPI port emptying pull pressure to move the transport liquid to the tip of the electrospray electrode, illustrated as 116 FIG. 1. The balance of the OPI port emptying pull pressure may also be available for sample aspiration. During the sampling event, while the inlet port 307 is in contact with the liquid sample 302, the combination of the “starved” transport flow and the sample aspiration rate may result in a closed flow through the removal conduit 308 as the liquid supply from the sample reservoir overcomes or balances the transport flow supply limitation, thus increasing the resulting signal.

[0072]

[0071] FIG. 6B illustrates a balanced flow mode, in accordance with examples of this disclosure. When operating in a balanced flow mode illustrated in FIG. 6B, the meniscus 660 of the transport liquid or sample 662 flowing within the OPI 600 remains substantially flush with a bottom portion of the tip or inlet port 658 because about the same amount of transport liquid and sample comes into the inlet port 658 as is aspired through the removal conduit 656. Operating with transport flow supply at the balanced flow allows effective termination of the sample plug (LS) as switching into this transport flow stops sample aspiration and creates a closed flow plug necessary for effective clearance of sample chemical memory effects in the sampling conduits. In practice termination of the sample aspiration may also include removal of the inlet port 658 from the liquid sample.

[0073]

[0072] FIG. 6C illustrates an under-pumped flow mode, also referred to herein as overflow mode, in accordance with examples of this disclosure. When operating in an overflow mode as illustrated in FIG. 6C, the meniscus 660 of the transport liquid or sample 662 flowing within the OPI 600 may extend further than the bottom portion of the tip or inlet port 658 because a larger amount of transport liquid and sample comes into the inlet port 658 than is aspired through the removal conduit 656. Operating under this condition may over time lead to droplet formation at the tip of the inlet port 658 and allow wash of the outer surface of the lower portion of inlet port 658 to reduce chemical memory effects. This transport flow mode offers a combination of liquid sample termination (as described above) with inlet port outside wall wash.

[0074]

[0073] FIGS. 7 A and 7B are flow charts illustrating methods for operating an OPI, in accordance with various examples of the disclosure. The OPI may be an OPI of a sample analysis system, may include therein a transport liquid conduit and a sample removal conduit and may be configured to flow a transport liquid therethrough from the transport liquid conduit to a capture region of the OPI to the sample removal conduit. In FIG. 7A, operation 710 includes introducing the OPI at a liquid sample in a sample reservoir while supplying the transport liquid at a first flow rate to the OPI, e.g., to a capture region of the OPI. Supplying the transport liquid at the first flow rate may include supplying the transport liquid at a flow rate in a range of 0% to 60% of a balanced flow. For example, supplying the transport liquid at the first flow rate may include supplying the transport liquid at a flow rate in a range of 0% to 10%, 10% to 20%, 20% to 30%, 30% to 40%, 40% to 50% and 50% to 60% of a balanced flow. In addition, supplying the transport liquid at the first flow rate may include supplying the transport liquid at a flow rate in a range of 10% to 50%, 20% to 40%, and 30% of a balanced flow.

[0075]

[0074] Operation 720 includes aspirating a first amount of the liquid sample through the removal conduit via the transport liquid flowing at the first flow rate, e.g., via the transport liquid flowing through the OPI. Operation 730 includes determining whether a first condition is met. The first condition may be or include, e.g., a first period of time before the tip of the OPI touches the liquid sample in the sample reservoir. The first period of time may be, e.g., a period of time in a range of 0.001 seconds to 20 seconds. Alternatively, the first condition may be or include a time of contact between the tip of the OPI and the liquid sample in the sample reservoir. For example, the time of contact may be in a range of 0.001 second to about 20 seconds. The first condition may also be, e.g., a second period of time after the tip of the OPI touches the liquid sample in the sample reservoir. The second period of time may be a period of time in a range of 0.001 seconds to 20 seconds. During operation 730, if the first condition is met, then the method 700 continues to operation 740, and if the first condition is not met, then the method 700 may continue to operation 710, during which the OPI continues to be introduced in the sample reservoir.

[0076]

[0075] Operation 740 includes switching a flow rate of the transport liquid flowing through the OPI from the first flow rate to a second flow rate to, e.g., the capture region of the OPI. The second flow rate may be different from the first flow rate. For example, the second flow rate may be greater than the first flow rate, so that during operation 740, the transport liquid goes from a low flow rate, i.e., a starved or over-pumped flow rate, to a high flow rate, i.e., a less starved flow rate, a balanced flow rate, or an overflow flow rate. During operation 740, switching the flow rate of the transport liquid to the second flow rate may include supplying a flow rate in a range of 40% to 100% of a balanced flow rate. Alternatively, switching the flow rate of the transport liquid to the second flow rate may also include switching to a flow rate in a range of 40% to 50% of the balanced flow rate, 50% to 60% of the balanced flow rate, 60% to 70% of the balanced flow rate, 70% to 80% of the balanced flow rate, or 80% to 100% of the balanced flow rate. Switching the flow rate of the transport liquid to the second flow rate may include switching to a flow rate in a range of 50% to 90% of the balanced flow rate, 60% to 110% of the balanced flow rate, or about 70% of the balanced flow rate. Switching the transport liquid flow rate from the first flow rate to the second flow rate during operation 740 may be performed within a third period of time that is less than 500 ms. For example, the third period of time may be in a range of 10 ms to 500 ms.

[0077]

[0076] Operation 740 may contemporaneously or alternatively include extracting the OPI from the sample reservoir, where the liquid sample plug (LS) is terminated by the removal of the inlet port from the sample liquid and high transport flow. Accordingly, the second flow rate may continue to be applied to the OPI after extraction from the sample reservoir in order to, e.g., wash out the OPI of any remnant of the liquid sample. For example, the second flow rate may be applied for a period of time in a range of 0.001 second to about 60 seconds, or alternatively in a range of 1 second to about 20 minutes. In various examples, the method 700 may further include operation 750, during which a determination is made regarding whether a fourth period of time has lapsed. During operation 750, if the fourth period of time has lapsed, then the method 700 continues to operation 760, and if the fourth period of time has not lapsed, then the method 700 continues to operation 740. Operation 760 includes switching the flow of the transport liquid from the second flow rate to the first flow rate, and the method 700 continues to operation 710 to introduce the OPI in the sample reservoir for, e.g., another sample. For example, the fourth period of time may be in a range of 0.001 second to about 60 seconds, or alternatively in a range of 1 second to about 20 minutes.

[0078]

[0077] In other examples, switching the flow rate of the transport liquid during operation 740 may include switching the flow rate of the transport liquid from the first flow rate to a second flow rate that is lower than the first flow rate. In this case, the method 700 may switch back to the first flow rate in operation 710, or continue to the operations 750 and 760, where the liquid sample plug (LS) is terminated by the inlet port removal from the sample liquid and high transport flow. Switching the transport liquid flow rate from the first flow rate to the second flow rate, and vice versa, during operation 740 or 760 may be performed within a third period of time that is less than 500 ms. For example, the third period of time may be in a range of 10 ms to 500 ms.

[0078] In FIG. 7B, operations 715-745 are similar to operations 710-740 discussed above with respect to FIG. 7A. In FIG. 7B, the method 705 may further include operation 755, during which a second amount of liquid sample is aspirated through the removal conduit via the transport liquid flowing at the second flow rate, e.g., via the transport liquid flowing through the OPI. Aspirating the second amount of the liquid sample through the removal conduit may take place for a fourth period of time. The fourth period of time may be, e.g., in a range of about 0.01 second to 20 seconds.

[0079] Alternatively, the fourth period of time may be, e.g., about 3 seconds. During operation 765, a determination is made regarding whether the fourth period of time has lapsed. During operation 765, if the fourth period of time has lapsed, then the method 705 continues to operation 775, and if the fourth period of time has not lapsed, then the method 705 continues to operation 755, during which the second amount of liquid sample continues to be aspirated at the second flow rate. When the fourth period of time has lapsed as determined during operation 765, operation 775 includes extracting the OPI from the liquid sample and the sample reservoir while, e.g., switching flowrate of the transport liquid to the capture region of the OPI at a third flow rate. When the OPI is extracted from the sample reservoir during operation 775, the method 705 may return to operation 715 to start a new cycle of extracting the liquid sample from the sample reservoir. Alternatively, when the OPI is extracted from the sample reservoir during operation 775, operation 775 may also include performing a washout operation of the removal conduit of the OPI by introducing transport liquid therethrough at the second flow rate, the third flow rate, or at another higher flow rate. As a result, the removal conduit of the OPI may be clear of any liquid sample, and operation 715 may resume with another sample, either from the same sample reservoir or from a different sample reservoir. Sampling event duration, which is the time that the inlet port spends in the liquid sample may be in a range of about 0.001 sec to 20sec, a range of about O.Olsec to Isec, or a range of about Isec to 5sec.

[0080]

[0079] Alternatively, the process may continue to operation 755 that includes aspirating a second amount of the liquid sample through the removal conduit via the transport liquid flowing at the second flow rate or another flow rate, e.g., via the transport liquid flowing through the OPI. Aspirating the second amount of the liquid sample through the removal conduit may take place for a fourth period of time. The fourth period of time may be, e.g., in a range of about 0.01 second to 20 seconds. Alternatively, the fourth period of time may be, e.g., about 3 seconds.

[0081]

[0080] Now referring to FIG. 8, an example of the computing device 800 according to FIGS. 1 and 2 is illustrated and described. It is noted that the computing system 103 of the system 10 may include a single computing device 800 or may include a plurality of distributed computing devices 800 in operative communication with components of a mass analysis instrument 100. In the illustrated example of FIG. 8, the computing device 800 may include a bus 802 or other communication mechanism of similar function for communicating information, and at least one processing element 804 coupled with bus 802 for processing information. As is appreciated by those skilled in the relevant arts, such at least one processing element 804 may include a plurality of processing elements or cores, which may be packaged as a single processor or in a distributed arrangement. Furthermore, in some examples, a plurality of virtual processing elements 804 may be included in the computing device 800 to provide the control or management operations for the mass analysis instrument 100 illustrated in FIGS. 1 and 2, and for the valve 530 illustrated in FIG. 5.

[0082]

[0081] Computing device 800 may also include one or more volatile memory(ies) 806, which can for example include random access memory(ies) (RAM) or other dynamic memory component(s), coupled to one or more busses 802 for use by the at least one processing element 804. Computing device 800 may further include static, non-volatile memory(ies) 808, such as read only memory (ROM) or other static memory components, coupled to busses 802 for storing information and instructions for use by the at least one processing element 804. A storage component 810, such as a storage disk or storage memory, may be provided for storing information and instructions for use by the at least one processing element 804. As is appreciated, in some examples the computing device 800 may include a distributed storage component 812, such as a networked disk or other storage resource available to the computing device 800.

[0083]

[0082] Computing device 800 may be coupled to one or more displays 814 for displaying information to a computer user. Optional user input devices 816, such as a keyboard and / or touchscreen, may be coupled to a bus for communicating information and command selections to the at least one processing element 804. An optional graphical input device 818, such as a mouse, a trackball or cursor direction keys for communicating graphical user interface information and command selections to the at least one processing element. The computing device 800 may further include an input / output (I / O) component, such as a serial connection, digital connection, network connection, or other input / output component for allowing intercommunication with other computing components and the various components of the mass analysis instrument 100 illustrated in FIGS. 1 and 2, and for the valve 530 illustrated in FIG. 5.

[0084]

[0083] In various examples, computing device 800 can be connected to one or more other computer systems a network to form a networked system. Such networks can for example include one or more private networks, or public networks such as the Internet. In the networked system, one or more computer systems can store and serve the data to other computer systems. The one or more computer systems that store and serve the data can be referred to as servers or the cloud, in a cloud computing scenario. The one or more computer systems can include one or more web servers, for example. The other computer systems that send and receive data to and from the servers or the cloud can be referred to as client or cloud devices, for example. Various operations of the mass analysis instrument 100 and of the valve 530 may be supported by operation of the distributed computing systems.

[0085]

[0084] Computing device 800 may be operative to control operation of the components of the mass analysis instrument 100 and the sample delivery components 70, 80, 95, 105 through controller(s) 135 and to handle data generated by components of the mass analysis instrument 100 and the valve 530 through the data processing system 150. In some examples, analysis results are provided by computing device 800 in response to the at least one processing element 804 executing instructions contained in memory 806 or 808 and performing operations on data received from the mass analysis instrument 100 and the valve 530. Execution of instructions contained in memory 806 or 808 by the at least one processing element 804 can render the mass analysis instrument 100, associated sample delivery components 70, 80, 95, 105, and valve 530 operative to perform methods described herein. Alternatively, hard-wired circuitry may be used in place of or in combination with software instructions to implement the present teachings. Thus, implementations of the present teachings are not limited to any specific combination of hardware circuitry and software.

[0086]

[0085] The term “computer-readable medium” as used herein refers to any media that participates in providing instructions to processor 804 for execution. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media includes, for example, optical or magnetic disks, such as disk storage 810. Volatile media includes dynamic memory, such as memory 806. Transmission media includes coaxial cables, copper wire, and fiber optics, including the wires that include bus 802.

[0087]

[0086] Common forms of computer-readable media or computer program products include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, a CD-ROM, digital video disc (DVD), a Blu-ray Disc, any other optical medium, a thumb drive, a memory card, a RAM, PROM, and EPROM, a FLASH-EPROM, any other memory chip or cartridge, or any other tangible medium from which a computer can read.

[0088]

[0087] Various forms of computer readable media may be involved in carrying one or more sequences of one or more instructions to processor 804 for execution. For example, the instructions may initially be carried on the magnetic disk of a remote computer. The remote computer can load the instructions into its dynamic memory and send the instructions over a telephone line using a modem. A modem local to computer system 800 can receive the data on the telephone line and use an infra-red transmitter to convert the data to an infra-red signal. An infra-red detector coupled to bus 802 can receive the data carried in the infra-red signal and place the data on bus 802. Bus 802 carries the data to memory 806, from which processor 804 retrieves and executes the instructions. The instructions received by memory 806 may optionally be stored on storage device 810 either before or after execution by processor 804.

[0089]

[0088] In accordance with various examples, instructions configured to be executed by a processor to perform a method are stored on a computer-readable medium. The computer-readable medium can be a device that stores digital information. For example, a computer-readable medium includes a compact disc read-only memory (CD-ROM) as is known in the art for storing software. The computer-readable medium is accessed by a processor suitable for executing instructions configured to be executed.

[0089] Although some aspects have been described in the context of an apparatus, it is clear that these aspects also represent a description of the corresponding method, where a block or device corresponds to a method step or a feature of a method step. Analogously, aspects described in the context of a method step also represent a description of a corresponding block or item or feature of a corresponding apparatus. Some or all of the method steps may be executed by (or using) a hardware apparatus, like for example, a processor, a microprocessor, a programmable computer, or an electronic circuit. In some examples, some one or more of the most important method steps may be executed by such an apparatus.

[0090]

[0090] Generally, examples of the present disclosure can be implemented through the use of computer program products with program codes, the program codes being operative for performing the operations described herein when the computer program product runs on a computer such as may be used to embody any or all of controllers such as, 135, 82, 92, 96, 107, or 137.

[0091]

[0091] Although various examples and examples are described herein, those of ordinary skill in the art will understand that many modifications may be made thereto within the scope of the present disclosure. Accordingly, it is not intended that the scope of the disclosure in any way be limited by the examples provided.

Claims

CLAIMSWhat is claimed is:

1. A method of operating an open port interface (OPI) of a sample analysis system, the OPI comprising a transport liquid conduit and a sample removal conduit and being configured to flow a transport liquid therethrough from the transport liquid conduit to a capture region of the OPI to the sample removal conduit, the method comprising: introducing the OPI at a liquid sample in a sample reservoir while supplying the transport liquid at a first flow rate to the capture region; aspirating a first amount of the liquid sample through the removal conduit via the transport liquid flowing at the first flow rate; and switching a flow rate of the transport liquid flowing through the OPI from the first flow rate to a second flow rate when a first condition is met, the second flow rate being different from the first flow rate.

2. The method of claim 1, further comprising aspirating a second amount of the liquid sample through the removal conduit via the transport liquid flowing at the second flow rate.

3. The method of claim 1 or claim 2, wherein the second flow rate is greater than the first flow rate.

4. The method of any one of claims 1-3, wherein supplying the first flow rate comprises supplying a flow rate in a range of 0% to 60% of a balanced flow rate.

5. The method of any one of claims 1-4, wherein switching the flow rate of the transport liquid to the second flow rate comprises supplying a flow rate in a range of 40% to 110% of a balanced flow rate.

6. The method of any one of claims 1-5, wherein the first condition comprises a first period of time before a tip of the OPI touches the liquid sample in the sample reservoir.

7. The method of claim 6, wherein the first period of time comprises a period of time in a range of 0.001 seconds to 20 seconds.

8. The method of any one of claims 1-7, wherein the first condition comprises a time of contact between a tip of the OPI and the sample in the sample reservoir.

9. The method of claim 8, wherein the time of contact between the tip of the OPI and the sample in the sample reservoir is in a range of 0.001 second and 20 seconds.

10. The method of any one of claims 1-9, wherein the first condition comprises a second period of time after a tip of the OPI touches the sample in the sample reservoir.

11. The method of claim 10, wherein the second period of time comprises a period of time in a range of 0.001 seconds to 20 seconds.

12. The method of any one of claims 1-11, wherein switching the flow rate of the transport liquid to the second flow rate is performed within a third period of time.

13. The method of claim 12, wherein the third period of time is less than 500 ms.

14. The method of claim 12 or claim 13, wherein the third period of time is in a range of 10 ms to 500 ms.

15. The method of any one of claims 2-14, wherein one of aspirating the first amount of the liquid sample and aspirating the second amount of the liquid sample through the removal conduit comprises aspirating the first or second amount of the liquid sample for a fourth period of time.

16. The method of claim 15, wherein the fourth period of time comprises a period of time in a range of about 0.001 second to 20 seconds.

17. The method of claim 15 or claim 16, wherein the fourth period of time comprises a period of time of about 3 seconds.

18. The method of any one of claims 15-17, further comprising extracting the OPI from the sample while supplying a third flow of the transport liquid to the OPI after the fourth period of time has elapsed.

19. A transport liquid flow control apparatus comprising: a selectable valve comprising a single valve inlet and a pair of valve outlets; an inlet conduit fluidly coupling a transport liquid reservoir to the single valve inlet; a first resistance flow path fluidly coupling a first valve outlet of the pair of valve outlets to the OPI, wherein the first resistance flow path has a first flow resistance; and a second resistance flow path fluidly coupling a second valve outlet of the pair of valve outlets to the OPI, wherein the second resistance flow path has a second flow resistance higher than the first flow resistance.

20. The apparatus of claim 19, wherein the first resistance flow path is configured to generate a liquid flow rate in a range of 0% - 60% of a balanced flow rate.

21. The apparatus of claim 19 or claim 20, wherein the second resistance flow path is configured to generate a liquid flow rate in a range of 40% - 1000% of a balanced flow rate.

22. A sample analyzing system comprising: a sample reservoir; the transport liquid flow control apparatus of claim 17 coupled to an OPI, the OPI comprising a transport liquid conduit and a sample removal conduit; a sample ionization device fluidly coupled to the OPI; a sample analysis device coupled to the sample ionization device; at least one controller operatively coupled to the sample reservoir, the transport liquid flow control apparatus, the sample ionization device and the sample analysis device; and a memory coupled to the at least one controller, the memory storing instructions that, when executed by the controller, performs a set of operations comprising:introducing, via the at least one controller, the OPI at a liquid sample in the sample reservoir while supplying the transport liquid at a first flow rate to a capture region of the OPI; aspirating, via the transport liquid flow control apparatus, a first amount of the liquid sample through the removal conduit via the transport liquid flowing at the first flow rate; and switching, via the transport liquid flow control apparatus, a flow rate of the transport liquid flowing through the OPI from the first flow rate to a second flow rate when a first condition is met, the second flow rate being different from the first flow rate.

23. The system of claim 22, wherein the set of operations further comprises: aspirating, via the transport liquid flow control apparatus, a second amount of the liquid sample through the removal conduit via the transport liquid flowing at the second flow rate.

24. The system of claim 22 or claim 23, wherein the set of operations comprises supplying the transport liquid at the first flow rate by supplying the transport liquid at a flow rate in a range of 0% to 60% of a balanced flow rate.

25. The system of any one of claims 22-24, wherein the set of operations comprises switching the flow rate of the transport liquid flowing through the OPI to the second flow rate by supplying a flow rate of the transport liquid in a range of 40% to 110% of a balanced flow rate.

26. The system of any one of claims 22-25, wherein the first condition comprises one of: a first period of time before a tip of the OPI touches the liquid sample in the sample reservoir; a time of contact between a tip of the OPI and the liquid sample in the sample reservoir; and a second period of time after a tip of the OPI touches the liquid sample in the sample reservoir.

27. The system of any one of claims 22-26, wherein the set of instructions further comprises performing switching the flow rate of the transport liquid flowing through the OPI to the second flow rate within a third period of time.

28. The system of claim 27, wherein the third period of time is less than 500 ms.

29. The system of claim 28, wherein the third period of time is in a range of 10 ms to 500 ms.

30. The system of any one of claims 23-29, wherein the set of instructions comprises aspirating the first amount of the liquid sample or the second amount of the liquid sample through the removal conduit by aspirating the first or second amount of the liquid sample for a fourth period of time.

31. The system of claim 30, wherein the fourth period of time comprises a period of time in a range of 0.01 second to 20 seconds.

32. The system of claim 30 or claim 31, wherein the fourth period of time comprises a period of time of about 3 seconds.

33. The system of any one of claims 30-32, wherein the set of instructions further comprises extracting the OPI from the liquid sample while supplying a third flow of the transport liquid to the capture region of the OPI after the fourth period of time has elapsed.

34. The system of any one of claims 22-33, wherein: the sample reservoir is one of a plurality of wells in a well plate; and the sample is in one of the plurality of wells.

35. The system of any one of claims 22-34, wherein the sample analysis device comprises at least one of a differential mobility spectrometer (DMS), a mass spectrometer (MS or MS / MS), and a DMS / MS.

36. The system of any one of claims 22-35, wherein the sample ionization device comprises one of a DESI device, a MALDI device, a LAP-MALDI device, a rapid-fire mass spectrometer, a pneumatic ESI device, and an El device.

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