Liquid chromatographic analysis system and gradient elution control method

Abstract

The invention relates to the technical field of chromatographic analysis, and discloses a liquid chromatographic analysis system and a gradient elution control method.The method is applied to the liquid chromatographic analysis system.The method comprises the steps that in response to a sample introduction instruction, a sample introduction channel is controlled to be communicated, and a sample introduction device is controlled to convey a sample into a sample cache assembly; a liquid phase channel is controlled to be communicated with the other two interfaces except the sample caching assembly, and the initial circulation phase is enabled to circulate in a channel currently formed by the mobile phase conveying assembly, the switching assembly and the chromatographic column; determining the starting time of the delay volume time according to the sampling time and the delay volume time; when the starting moment of the delayed volume time is reached, the mobile phase conveyed out through the gradient proportional mixing valve is a target mobile phase; and when the end time of the sample introduction time is reached, controlling the sample introduction passage to be disconnected and the liquid phase passage to be connected, so that the sample in the sample cache assembly is pushed to enter the chromatographic column through the target mobile phase at the zero point of the liquid phase gradient. According to the method, the influence of the delay volume can be eliminated.

Description

Technical Field

[0001] The present application relates to the technical field of chromatography analysis, and in particular to a liquid chromatography analysis system and a gradient elution control method. Background Art

[0002] Liquid chromatograph is a commonly used analytical instrument that separates different components in a sample between a stationary phase and a mobile phase. In liquid chromatography, it is sometimes necessary to change the composition of the mobile phase to better separate the sample, but there is a delay volume between the mixing of the mobile phase and the sample entering the chromatographic column. The existence of the delay volume affects the speed of the gradient change, thereby affecting the separation effect. The larger the delay volume, the slower the gradient change and the longer the analysis time.

[0003] In order to reduce the liquid phase delay volume, the following methods are generally used in the prior art:

[0004] First, optimize the solvent mixer and connecting pipe: select a smaller solvent mixer to reduce the volume of the mixer itself; use thinner and shorter connecting pipes to reduce the volume in the connecting pipe. Within the pressure range, try to choose pipes with small inner diameter and short length. However, this method can only reduce the size of the delay volume, but cannot eliminate the impact of the delay volume. At the same time, it increases the difficulty of design layout, and the pressure loss of the pipeline will also increase.

[0005] Second, use a high-pressure pump, because high-pressure pumps usually have a more compact design, which can reduce the contribution of the pump volume to the delay volume, ensure the sealing and efficiency of the pump head, and avoid unnecessary volume increase. However, this method has higher requirements for materials and sealing, increases design difficulty, and significantly increases product costs.

[0006] Third, consider the gradient elution method: In the gradient elution method, the gradient delay effect caused by the delay volume can be reduced by optimizing the rate and shape of the gradient change, which usually involves adjusting the parameters of the gradient program, such as the gradient slope, the initial and target mobile phase ratio, etc. However, this method cannot eliminate the influence of the delay volume, and changing the gradient change rate and shape will affect the liquid phase separation efficiency, which is not conducive to the separation of compounds with high gradient requirements. Summary of the invention

[0007] In view of this, the embodiments of the present application provide a liquid chromatography analysis system and a gradient elution control method, which can effectively eliminate the influence of the delay volume on the gradient analysis.

[0008] In a first aspect, an embodiment of the present application provides a liquid chromatography analysis system, comprising: a mobile phase supply component, a gradient ratio mixing valve, a mobile phase delivery component, a switching component, an injection device, a chromatographic column, and a detector;

[0009] The switching component includes an injection passage and a liquid phase passage; wherein the injection passage and the liquid phase passage share a sample cache component, and when the injection passage is turned on, the liquid phase passage is disconnected from the sample cache component, and when the liquid phase passage is turned on, the injection passage is disconnected from the sample cache component;

[0010] The inlet of the injection passage is connected to the injection device;

[0011] The mobile phase supply component, the gradient ratio mixing valve and the mobile phase delivery component are connected in sequence and connected to the inlet of the liquid phase passage of the switching component;

[0012] The outlet of the liquid phase passage, the chromatographic column and the detector are connected in sequence.

[0013] In some embodiments, the switching component is a six-way valve, and the six-way valve includes a first interface, a second interface, a third interface, a fourth interface, a fifth interface, a sixth interface and a sample cache component; wherein the sample cache component is connected between the first interface and the fourth interface;

[0014] The injection path is a path formed by the third interface, the fourth interface, the sample buffer component, the first interface and the second interface;

[0015] The liquid phase passage is a passage formed by the fifth interface, the fourth interface, the sample cache component, the first interface and the sixth interface;

[0016] The mobile phase supply component, the gradient ratio mixing valve and the mobile phase delivery component are connected in sequence and connected to the fifth interface of the six-way valve;

[0017] The sample injection device is communicated with the third interface of the six-way valve;

[0018] The sixth interface of the six-way valve, the chromatographic column and the detector are connected in sequence.

[0019] In some embodiments, the mobile phase supply assembly includes at least two independent solvent bottles and a degasser;

[0020] The degasser comprises at least two groups of degassing interfaces, each group of the degassing interfaces is connected to one of the solvent bottles, and transmits the liquid phase in the corresponding solvent bottle to the gradient ratio mixing valve.

[0021] In some embodiments, the mobile phase delivery assembly includes a first delivery pump, a second delivery pump, and a mixer;

[0022] A one-way valve is installed on the pipelines in front of the first delivery pump and the second delivery pump respectively;

[0023] The inlet of the mixer is in communication with the outlet of the second delivery pump;

[0024] The outlet of the mixer is in communication with the inlet of the liquid phase passage.

[0025] In some embodiments, the injection device includes a syringe, a sample bottle, and an injection needle;

[0026] The syringe is used to control the injection needle to draw a sample from the sample bottle and push the sample into the injection passage.

[0027] In some embodiments, the system further comprises a cleaning component;

[0028] The cleaning assembly includes a cleaning bottle for placing cleaning liquid;

[0029] When the sample injection device is cleaned, the second interface is communicated with the third interface.

[0030] In a second aspect, an embodiment of the present application provides a gradient elution control method, which is applied to the above-mentioned liquid chromatography analysis system, comprising:

[0031] In response to the sampling instruction, controlling the sampling passage to be turned on, and controlling the sampling device to deliver the sample to the sample buffer component; and

[0032] Controlling the liquid phase passage to communicate with two interfaces other than the sample buffer assembly, and controlling the gradient proportion mixing valve according to a preset first proportion parameter, so that the initial flow phase flows in the passage currently composed of the mobile phase delivery assembly, the switching assembly and the chromatographic column; and

[0033] Determine the starting time of the delayed volume time according to the injection time and the delayed volume time;

[0034] When the start time of the delayed volume time is reached, the gradient proportion mixing valve is controlled according to a preset second proportion parameter so that the mobile phase delivered through the gradient proportion mixing valve is the target mobile phase;

[0035] When the injection time ends, the injection passage is controlled to be disconnected and the liquid phase passage is connected, so that the sample in the sample buffer component is pushed into the chromatographic column through the target mobile phase at the zero point of the liquid phase gradient.

[0036] In some embodiments, the injection time is calculated based on the sample suction time and the mechanical movement time, or calculated based on the sample suction time, the mechanical movement time and the cleaning time; wherein the sample suction time is the time taken by the injection needle of the injection device to suck up the sample each time, and the mechanical movement time is the time taken by the injection needle each time to push the injection needle to transfer the sample in the injection needle to the sample buffer component when the injection needle sucks up the sample; the cleaning time is the time taken to clean the injection needle;

[0037] The delay volume time is calculated based on the flow velocity of the mobile phase in the mobile phase delivery component and the delay volume; wherein the delay volume is the spatial volume inside the gradient proportion mixing valve and the mobile phase delivery component, plus the sum of the volumes inside all pipelines between the gradient proportion mixing valve and the sample cache component.

[0038] In some embodiments, the controlling the conduction of the injection passage comprises:

[0039] Control the first interface and the second interface of the switching component to be connected, and the third interface and the fourth interface to be connected;

[0040] The control liquid phase passage is connected to two interfaces other than the two interfaces connected to the sample cache component, including:

[0041] The first interface and the sixth interface of the control switching component are disconnected, the fourth interface and the fifth interface are disconnected, and the fifth interface and the sixth interface are connected.

[0042] In some embodiments, the controlling of disconnecting the injection passage and connecting the liquid phase passage comprises:

[0043] Control the first interface and the second interface of the switching component to be disconnected, and the third interface and the fourth interface to be disconnected;

[0044] And control the first interface to be connected to the sixth interface, the fourth interface to be connected to the fifth interface, and the fifth interface to be disconnected from the sixth interface.

[0045] The embodiment of the present application has the following beneficial effects: the present application controls the conduction of the injection channel after receiving the injection instruction, and then starts to transport the sample to the sample buffer component, and at the same time starts to transport the initial mobile phase to the passage currently composed of the mobile phase delivery component, the switching component and the chromatographic column, and at the same time needs to determine the starting time of the delay volume time. When the starting time of the delay volume is reached, the gradient ratio mixing valve is controlled according to the preset second proportional parameter to start transporting the target mobile phase to the passage currently composed of the mobile phase delivery component, the switching component and the chromatographic column, and at the end of the injection, the injection passage is controlled to be disconnected and the liquid phase passage is connected. Since the end time of the injection time is the same as the end time of the delay volume time, that is to say, at the moment when the injection is completed, the delay volume is also filled with the target mobile phase, so that at the end of the injection, it can be ensured that the zero point of the liquid phase gradient directly causes the target mobile phase to push the sample in the sample buffer component into the chromatographic column for analysis. The delivery time of the target mobile phase is determined by the injection time and the delay volume time in the present application, so as to eliminate the influence of the delay volume on the gradient time, thereby optimizing the separation effect and improving the analysis efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0047] Figure 1 A first structural schematic diagram of a liquid chromatography analysis system according to an embodiment of the present application is shown;

[0048] Figure 2 A second structural schematic diagram of the liquid chromatography analysis system according to an embodiment of the present application is shown;

[0049] Figure 3 A schematic flow chart of a gradient elution control method according to an embodiment of the present application is shown;

[0050] Figure 4 A timing diagram of gradient elution according to an embodiment of the present application is shown.

[0051] Description of main component symbols:

[0052] 100-mobile phase supply assembly; 200-gradient ratio mixing valve; 300-mobile phase delivery assembly; 400-switching assembly; 500-injection device; 600-chromatographic column; 700-detector; 110-solvent bottle; 120-degasser; 310-first delivery pump; 320-second delivery pump; 330-mixer; 410-sample cache assembly; 510-syringe; 520-sample bottle; 530-injection needle; 610-cleaning bottle. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0054] The components of the embodiments of the present application generally described and shown in the drawings herein may be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0055] Hereinafter, the terms "including", "having" and their cognates that can be used in various embodiments of the present application are intended only to indicate specific features, numbers, steps, operations, elements, components or a combination of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or a combination of the foregoing items or increasing the possibility of one or more features, numbers, steps, operations, elements, components or a combination of the foregoing items. In addition, the terms "first", "second", "third" and the like are only used to distinguish descriptions and cannot be understood as indicating or implying relative importance.

[0056] Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meanings as those generally understood by those skilled in the art to which the various embodiments of the present application belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meanings as the contextual meanings in the relevant technical field and will not be interpreted as having idealized meanings or overly formal meanings unless clearly defined in the various embodiments of the present application.

[0057] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0058] Liquid chromatographs use the difference in distribution coefficients between the stationary phase and the mobile phase of different components in the sample to achieve separation. Among them, the stationary phase is the porous granular material filled in the chromatographic column, and the mobile phase is the solvent that carries the sample through the chromatographic column. Due to the different interaction forces between the stationary phase and the mobile phase, their movement speeds in the chromatographic column will also be different, thereby achieving separation. Liquid phase gradient elution is an important technology in liquid chromatography separation. During the gradient elution process, the composition of the mobile phase can change within a certain range (such as 0%-100%). For example, within 60 minutes, the mobile phase ratio can change from methanol: water = 1:99 to methanol: water = 100:0. This change gradually increases the polarity of the mobile phase, thereby separating compounds of different polarities.

[0059] The liquid phase delay volume (also called gradient delay volume or retention volume) mainly refers to the volume from the solvent mixing point (usually in the mixing chamber, pipeline or proportional valve of the liquid chromatograph) to the inlet of the sample buffer component. This volume plays a key role in the liquid chromatography system, especially in the gradient elution method, the size of the delay volume has a direct impact on the gradient change speed. The smaller the delay volume, the faster it can be applied to the chromatographic column after adjusting the mobile phase ratio, thereby affecting the change of the mobile phase ratio in the chromatographic column, and then affecting the separation and analysis time.

[0060] Combine the following Figure 1 , Figure 2 The liquid chromatography analysis system of this embodiment is described.

[0061] like Figure 1 As shown, the liquid chromatography analysis system includes a mobile phase supply component 100, a gradient ratio mixing valve 200, a mobile phase delivery component 300, a switching component 400, a sample injection device 500, a chromatographic column 600, and a detector 700.

[0062] The switching component 400 includes an injection passage and a liquid phase passage; wherein the injection passage and the liquid phase passage share a sample buffer component 410, when the injection passage is on, the liquid phase passage is disconnected from the sample buffer component 410, and when the liquid phase passage is on, the injection passage is disconnected from the sample buffer component 410; the inlet of the injection passage is connected to the injection device 500; the mobile phase supply component 100, the gradient ratio mixing valve 200 and the mobile phase delivery component 300 are connected in sequence and connected to the inlet of the liquid phase passage of the switching component 400; the outlet of the liquid phase passage, the chromatographic column 600 and the detector 700 are connected in sequence. wherein the gradient ratio mixing valve 200 is used to mix the liquid phase solvent delivered from the mobile phase supply component 100 into a liquid phase of a preset ratio. wherein the sample buffer component 410 can be, but is not limited to, a structure that can buffer samples, such as a quantitative loop and a flow-through seat.

[0063] The mobile phase supply assembly 100 includes at least two independent solvent bottles 110 and a degasser 120; the degasser 120 includes at least two groups of degassing interfaces, each group of degassing interfaces is connected to a solvent bottle 110, and transmits the liquid phase in the corresponding solvent bottle 110 to the gradient ratio mixing valve 200. It can be understood that each solvent bottle 110 in the mobile phase supply assembly 100 contains a different liquid phase solvent, and the liquid phase solvent can be water, methanol, acetonitrile or other suitable solvents, and the degasser 120 is used to remove the gas in the liquid phase solvent transported from the solvent bottle 110.

[0064] The mobile phase delivery assembly 300 includes a first delivery pump 310, a second delivery pump 320 and a mixer 330; a one-way valve is installed on the pipelines in front of the first delivery pump 310 and the second delivery pump 320, respectively, to prevent the reverse flow of the liquid phase solvent delivered from the first delivery pump 310 and the second delivery pump 320. The inlet of the mixer 330 is connected to the outlet of the second delivery pump 320; the outlet of the mixer 330 is connected to the inlet of the liquid phase passage. The first delivery pump 310 and the second delivery pump 320 are both plunger pumps. In this embodiment, two delivery pumps are provided to prevent the liquid phase from being interrupted.

[0065] The switching component 400 is a six-way valve, which includes a sample buffer component 410 and a first interface to a sixth interface, which correspond to Figure 1 and Figure 2 The interfaces a, b, c, d, e and f shown in the figure. The sample cache component 410 is connected between the first interface and the fourth interface; the injection path is a path formed by the third interface, the fourth interface, the sample cache component 410, the first interface and the second interface; the liquid phase path is a path formed by the fifth interface, the fourth interface, the sample cache component 410, the first interface and the sixth interface; the mobile phase supply component 100, the gradient ratio mixing valve 200 and the mobile phase delivery component 300 are connected in sequence and connected to the fifth interface of the six-way valve; the injection device 500 is connected to the third interface of the six-way valve; the sixth interface of the six-way valve, the chromatographic column 600 and the detector 700 are connected in sequence.

[0066] In the liquid chromatography analysis system of the present embodiment, the solvent bottle 110 is used to provide a liquid phase, and the liquid phase enters the six-way valve after passing through the degasser 120, the gradient ratio mixing valve 200, the one-way valve, the first delivery pump 310, the second delivery pump 320, and the mixer 330 in sequence. Since the liquid chromatography analysis system needs to analyze the sample, it is necessary to first send the sample to be analyzed into the sample cache component 410, because the sample cache component 410 is between the first interface of the six-way valve and the fourth interface of the six-way valve. During the injection, the second interface of the six-way valve is communicated with the first interface of the six-way valve, and the third interface of the six-way valve is communicated with the fourth interface of the six-way valve. The injection device 500 is connected to the third interface of the six-way valve, and the injection device 500 pushes the sample into the sample cache component 410 through the third interface of the six-way valve.

[0067] After the sample cache assembly 410 is filled with samples, the fourth interface of the six-way valve is controlled to be connected to the fifth interface of the six-way valve, and the first interface of the six-way valve is connected to the sixth interface of the six-way valve, so that the liquid phase entering from the mixer 330 through the fifth interface of the six-way valve can promote separation in the sample chromatography column 600 in the sample cache assembly 410.

[0068] In some embodiments, the sample injection device 500 includes a syringe 510, a sample bottle 520, and a sample injection needle 530. When the sample needs to be delivered to the sample buffer assembly 410, the syringe 510 pushes the sample injection needle 530, thereby sucking the sample from the sample bottle 520 through the sample injection needle 530, and then the syringe 510 pushes the sucked sample into the sample buffer assembly 410.

[0069] In some embodiments, the liquid chromatography analysis system may be a liquid chromatography analysis system of a liquid phase quaternary low pressure system.

[0070] The liquid chromatography analysis system of the liquid phase quaternary low-pressure system includes four solvent bottles 110 (as shown in the figure, including solvent bottle 110A, solvent bottle 110B, solvent bottle 110C and solvent bottle 110D). In the liquid chromatograph, the number of interfaces of the degasser 120 corresponds to that of the solvent bottles 110, and each is also connected to an interface of the degasser 120. After the gas in the liquid is removed by the degasser 120, it enters the gradient proportion mixing valve 200. The number of interfaces of the gradient proportion mixing valve 200 is also the same as that of the solvent bottle 110, that is, the liquid phase coming out of each interface of the degasser 120 is transmitted from the interface corresponding to the gradient proportion mixing valve 200 through the first delivery pump 310 and the second delivery pump 320 to the mixer 330, and the liquid phase is mixed evenly in the mixer 330 and then transmitted to the six-way valve.

[0071] Among them, the four solvent bottles 110 are respectively loaded with different solvents or mobile phases, which can be water, methanol, acetonitrile or other suitable solvents. The gradient ratio mixing valve 200 can mix different solvents according to the set ratio to form the required mobile phase ratio; the mixer 330 is used to further evenly mix the solvents to ensure that the mixed mobile phase has a uniform composition. The pump is used to push the mobile phase mixed by the gradient ratio mixing valve 200 into the mixer 330. The pump of the quaternary low-pressure system is usually a constant flow pump, which can provide a stable mobile phase flow rate.

[0072] In some embodiments, the liquid chromatography analysis system can be a liquid chromatography analysis system of a binary high pressure system. The difference between the liquid chromatography analysis system of the binary high pressure system and the liquid chromatograph of the above-mentioned liquid phase quaternary low pressure system is the number of solvent bottles 110, the degasser 120 and the gradient ratio mixing valve 200. In the liquid chromatograph of the binary high pressure system, the solvent bottles 110 are two independent solvent bottles 110, the two interfaces of the degasser 120 are respectively connected to the two solvent bottles 110, and the interfaces of the gradient ratio mixing valve 200 are also two, which are respectively connected to the interfaces of the corresponding degasser 120. The remaining components are the same as those in the above-mentioned embodiment and will not be repeated here.

[0073] In some embodiments, the system further includes a cleaning component; the cleaning component includes a cleaning bottle 610 for placing a cleaning solution; when cleaning the injection device 500, the second interface is connected to the third interface, the first interface is disconnected from the second interface, and the third interface is disconnected from the fourth interface. The cleaning bottle 610 can also be connected to the degasser 120. After the last chromatographic analysis, when the next chromatographic analysis is performed, the injection needle 530 needs to be cleaned. The cleaning solution in the cleaning bottle 610 is first degassed by the degasser 120, and then passes through the passage formed by the second interface and the third interface, and then the injection needle 530 is cleaned.

[0074] According to the above-mentioned liquid chromatography analysis system, its liquid phase delay volume is the spatial volume inside components such as the gradient proportion mixing valve 200, the one-way valve, the first delivery pump 310, the second delivery pump 320, the mixer 330, etc., plus the volume inside all pipelines from the gradient proportion mixing valve 200 to the sample cache component 410.

[0075] Based on the above-mentioned liquid chromatography analysis system, the gradient elution control method is described in combination with some specific embodiments.

[0076] Figure 3 A schematic flow chart of a gradient elution control method according to an embodiment of the present application is shown.

[0077] Exemplarily, the gradient elution control method comprises the following steps:

[0078] Step S100, in response to the sampling instruction, the sampling passage is controlled to be turned on, and the sampling device is controlled to deliver the sample to the sample buffer component.

[0079] Step S200, controlling the liquid phase passage to be connected to two interfaces other than the sample buffer assembly, and controlling the gradient proportion mixing valve according to a preset first proportion parameter, so that the initial flow phase flows in the passage currently composed of the mobile phase delivery assembly, the switching assembly and the chromatographic column.

[0080] Step S300, determining the delay time according to the injection time and the delay volume time.

[0081] It can be understood that there is no sequence for steps S100, S200 and S300, and they are all steps executed after the liquid chromatography analysis system receives the injection instruction.

[0082] After the liquid chromatography analysis system receives the injection instruction, it indicates that it needs to perform chromatographic analysis on the sample. Usually, when chromatographic analysis is required on the sample, in order to prevent the residue on the injection needle from affecting the sample, the injection is also included before step S100. When cleaning, the second interface and the third interface are controlled to be connected. After the cleaning liquid in the cleaning bottle passes through the degasser, the cleaning liquid passes through the passage formed by the second interface and the third interface to clean the injection needle.

[0083] After cleaning the injection needle, the injection passage is controlled to be open, so that the injection device can be controlled to deliver the sample to the sample buffer assembly. While controlling the injection passage to be open, the remaining two interfaces of the liquid phase passage, except for the two interfaces connected to the sample buffer assembly, are controlled to be connected, so that the initial mobile phase can flow through the gradient ratio mixing valve, the mobile phase delivery assembly, the switching assembly and the chromatographic column in the currently formed channel, but there is no sample at this time, so the chromatographic column can not be analyzed, and the detector is not required for detection. Among them, the initial mobile phase is the mobile phase obtained by controlling the gradient ratio mixing valve according to the preset first ratio parameter, that is, the ratio relationship of the initial mobile phase will be set in advance, such as the mobile phase supply assembly includes two independent solvent bottles, water and methanol, respectively, and the ratio of water to methanol in the initial mobile phase is 99:1, then the gradient ratio mixing valve will be controlled to make the mixed mobile phase a 99:1 mobile phase of water and methanol.

[0084] In some embodiments, the switching component is a six-way valve, and the sample injection passage is controlled to be connected, and the sample injection device is controlled to deliver the sample to the sample buffer component, specifically: the first interface and the second interface of the switching component are controlled to be connected, and the third interface and the fourth interface are controlled to be connected. In addition, the sample injection device is connected to the third interface of the six-way valve, and after the sample injection passage is connected, the sample injection device can be controlled to deliver the sample to the sample buffer component.

[0085] The remaining two interfaces of the liquid phase passage, except the two interfaces connected to the sample buffer assembly, are controlled to be connected, specifically: the first interface and the sixth interface of the switching assembly are disconnected, the fourth interface and the fifth interface are disconnected, and the fifth interface and the sixth interface are connected. It can be understood that at this time, the liquid phase passage needs to be disconnected, but the fifth interface and the sixth interface need to be connected, so that the initial circulating phase flows in the passage formed by the mobile phase delivery assembly, the fifth interface and the sixth interface, and the passage formed by the chromatographic column.

[0086] In some embodiments, for the delay time in step S300, which is the liquid inlet time of the target mobile phase, specifically, the delay volume time is calculated based on the flow velocity of the mobile phase in the mobile phase delivery component and the delay volume. When the liquid chromatography analysis system is fixed, the flow velocity can be determined based on the pre-test situation. In addition, the delay volume is the volume of the space inside the gradient ratio mixing valve and the mobile phase delivery component plus the volume inside all pipelines between the gradient ratio mixing valve and the sample cache component. Since the liquid chromatography analysis system has been determined, the delay volume can also be determined. Therefore, when the delay volume and flow velocity are determined, the delay volume time can be calculated according to the following formula, and the formula is:

[0087] In the formula, T y is the delay volume time, S is the delay volume, and V is the flow velocity.

[0088] The injection time is calculated based on the sample suction time and the mechanical movement time, or calculated based on the sample suction time, the mechanical movement time, and the cleaning time.

[0089] Wherein, when the liquid chromatography analysis system is fixed, the sample injection device is also fixed. In this embodiment, the sample injection device is as follows: Figure 2 As shown, it includes a syringe, a sample bottle and a sampling needle. The sampling time is the time it takes for the sampling needle of the sampling device to absorb a sample each time. The mechanical movement time is the time it takes for the syringe of the sampling device to push the sampling needle to transport the sample in the sampling needle to the sample buffer component each time the sampling needle absorbs a sample. The cleaning time is the time it takes to clean the sampling needle. The sampling time, mechanical movement time and cleaning time can all be obtained based on prior experiments.

[0090] If the injection needle does not need to be cleaned, the injection time is calculated based on the sample aspiration time and the mechanical movement time. That is, based on the capacity of the injection needle and the capacity of the sample buffer component, it is determined how many times the injection needle needs to aspirate the sample, and the number of mechanical movements can be obtained. The injection time can be obtained by adding up the multiple sample aspiration times and the multiple mechanical movement times.

[0091] If the injection needle needs to be cleaned, the injection time is calculated based on the sample aspiration time, mechanical movement time and cleaning time. That is, based on the capacity of the injection needle and the capacity of the sample buffer component, it is determined how many times the injection needle needs to aspirate the sample, and the number of mechanical movements can also be obtained. The injection time can be obtained by adding the multiple sample aspiration times, multiple mechanical movement times and cleaning time.

[0092] After obtaining the injection time and delay volume time, as Figure 4 As shown, the starting time (T1 time) of the delay volume time can be obtained by subtracting the delay volume time (T1 time) from the injection time (T0 to T2 time), that is, Figure 4 As shown, the end time of the injection time and the end time of the delayed volume time are the same time, that is, both are time T2.

[0093] Step S400: When the start time of the delayed volume time is reached, the gradient proportion mixing valve is controlled according to a preset second proportion parameter so that the mobile phase delivered by the gradient proportion mixing valve is the target mobile phase.

[0094] Among them, the preset second ratio parameter is to make the mobile phase reach the mixing ratio of at least two solvents of the target mobile phase. When the sample is subjected to chromatographic analysis, the ratio relationship of each solvent in the target mobile phase is not necessarily fixed, and it can be variable. Therefore, in this step, the preset second ratio parameter is also variable. When controlling the gradient ratio mixing valve, the gradient ratio mixing valve should be controlled accordingly according to the variation rule of the preset second ratio parameter, so that the target mobile phase meets the variation requirements.

[0095] Step S500, when the injection time ends, the injection passage is controlled to be disconnected and the liquid phase passage is connected, so that the sample in the sample buffer assembly is pushed into the chromatographic column by the target mobile phase at the zero point of the liquid phase gradient.

[0096] The zero point of the liquid phase gradient is the moment when the gradient program starts to be executed, at which time the mobile phase ratio begins to change, that is, the starting point of the change from the initial mobile phase ratio to the target mobile phase ratio.

[0097] When the injection time is not over, the injection path is connected, and the liquid phase path is disconnected, that is, the second interface, the first interface, the sample buffer assembly, the fourth interface and the third interface of the six-way valve are connected, and the fifth interface and the sixth interface are connected. When the injection time ends, the injection is completed, and the target mobile phase is also filled with the delayed volume. At this time, the injection path is controlled to be disconnected and the liquid phase path is connected, that is, the first interface and the second interface are controlled to be disconnected, the third interface and the fourth interface are disconnected, and the sixth interface, the first interface, the quantitative exchange, the fourth interface and the fifth interface are controlled to be connected, so that it can be ensured that the target mobile phase directly pushes the sample in the sample buffer assembly into the chromatographic column for analysis at the zero point of the liquid phase gradient, and then the influence of the delayed volume can be eliminated. In this way, the sample is subjected to chromatographic analysis, and the actual analysis time of the liquid phase is the injection time plus the gradient time (T2-T3 time), then the actual analysis time is the time from T0 to T3, and the delayed volume time has been eliminated.

[0098] The present application controls the conduction of the injection channel after receiving the injection instruction, and then starts to transport the sample to the sample buffer component, and at the same time, starts to transport the initial mobile phase to the passage currently composed of the mobile phase delivery component, the switching component and the chromatographic column, and also needs to determine the starting time of the delay volume time. When the starting time of the delay volume is reached, the gradient ratio mixing valve is controlled according to the preset second proportional parameter to start transporting the target mobile phase to the passage currently composed of the mobile phase delivery component, the switching component and the chromatographic column, and at the end of the injection, the injection passage is controlled to be disconnected and the liquid phase passage is connected. Since the end time of the injection time is the same as the end time of the delay volume time, that is to say, at the moment when the injection is completed, the delay volume is also filled with the target mobile phase, so that at the end of the injection, it can be ensured that the zero point of the liquid phase gradient directly causes the target mobile phase to push the sample in the sample buffer component into the chromatographic column for analysis. The delivery time of the target mobile phase is determined by the injection time and the delay volume time in the present application, so as to eliminate the influence of the delay volume on the gradient time, and then the separation effect can be optimized and the analysis efficiency can be improved. Furthermore, by eliminating the influence of the delay volume on the gradient time in the manner of the present application, there is no need to change the structure of the original liquid phase analysis system and the hardware cost will not be increased.

[0099] The present application also provides a terminal device. Exemplarily, the terminal device includes a processor and a memory, wherein the memory stores a computer program, and the processor runs the computer program, thereby enabling the terminal device to execute the above-mentioned gradient elution control method.

[0100] Among them, the processor can be an integrated circuit chip with signal processing capabilities. The processor can be a general-purpose processor, including a central processing unit (CPU), a graphics processing unit (GPU) and a network processor (NP), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or at least one of other programmable logic devices, discrete gates or transistor logic devices, and discrete hardware components. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc., which can implement or execute the disclosed methods, steps and logic block diagrams in the embodiments of the present application.

[0101] The memory may be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), etc. The memory is used to store a computer program, and the processor may execute the computer program accordingly after receiving an execution instruction.

[0102] The present application also provides a computer-readable storage medium for storing the computer program used in the above-mentioned terminal device. For example, the computer-readable storage medium may include, but is not limited to, various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0103] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and structure diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in an alternative implementation, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the structure diagram and / or the flow diagram, and the combination of boxes in the structure diagram and / or the flow diagram, can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0104] In addition, the functional modules or units in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0105] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a smart phone, a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the various embodiments of the present application.

[0106] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A liquid chromatography analysis system, characterized in that: include: Mobile phase supply assembly, gradient ratio mixing valve, mobile phase delivery assembly, switching assembly, injection device, chromatographic column, detector; The switching component includes an injection passage and a liquid phase passage; wherein the injection passage and the liquid phase passage share a sample cache component, and when the injection passage is turned on, the liquid phase passage is disconnected from the sample cache component, and when the liquid phase passage is turned on, the injection passage is disconnected from the sample cache component; The inlet of the injection passage is connected to the injection device; The mobile phase supply component, the gradient ratio mixing valve and the mobile phase delivery component are connected in sequence and connected to the inlet of the liquid phase passage of the switching component; The outlet of the liquid phase passage, the chromatographic column and the detector are connected in sequence.

2. The liquid chromatography analysis system according to claim 1, characterized in that: The switching component is a six-way valve, which includes a first interface, a second interface, a third interface, a fourth interface, a fifth interface, a sixth interface and a sample cache component; wherein the sample cache component is connected between the first interface and the fourth interface; The injection path is a path formed by the third interface, the fourth interface, the sample buffer component, the first interface and the second interface; The liquid phase passage is a passage formed by the fifth interface, the fourth interface, the sample cache component, the first interface and the sixth interface; The mobile phase supply component, the gradient ratio mixing valve and the mobile phase delivery component are connected in sequence and connected to the fifth interface of the six-way valve; The sample injection device is communicated with the third interface of the six-way valve; The sixth interface of the six-way valve, the chromatographic column and the detector are connected in sequence.

3. The liquid chromatography analysis system according to claim 1, characterized in that: The mobile phase supply assembly includes at least two independent solvent bottles and a degasser; The degasser comprises at least two groups of degassing interfaces, each group of the degassing interfaces is connected to one of the solvent bottles, and transmits the liquid phase in the corresponding solvent bottle to the gradient ratio mixing valve.

4. The liquid chromatography analysis system according to claim 1, characterized in that: The mobile phase delivery assembly includes a first delivery pump, a second delivery pump and a mixer; A one-way valve is installed on the pipelines in front of the first delivery pump and the second delivery pump respectively; The inlet of the mixer is in communication with the outlet of the second delivery pump; The outlet of the mixer is in communication with the inlet of the liquid phase passage.

5. The liquid chromatography analysis system according to claim 1, characterized in that: The sample injection device comprises a syringe, a sample bottle and a sample injection needle; The syringe is used to control the injection needle to draw a sample from the sample bottle and push the sample into the injection passage.

6. The liquid chromatography analysis system according to claim 2, characterized in that: The system also includes a cleaning component; The cleaning assembly includes a cleaning bottle for placing cleaning liquid; When the sample injection device is cleaned, the second interface is communicated with the third interface.

7. A gradient elution control method, characterized in that: The liquid chromatography analysis system according to any one of claims 1 to 6 comprises: In response to the sampling instruction, controlling the sampling passage to be turned on, and controlling the sampling device to deliver the sample to the sample buffer component; and Controlling the liquid phase passage to communicate with two interfaces other than the sample buffer assembly, and controlling the gradient proportion mixing valve according to a preset first proportion parameter, so that the initial flow phase flows in the passage currently composed of the mobile phase delivery assembly, the switching assembly and the chromatographic column; and Determine the starting time of the delayed volume time according to the injection time and the delayed volume time; When the start time of the delayed volume time is reached, the gradient proportion mixing valve is controlled according to a preset second proportion parameter so that the mobile phase delivered through the gradient proportion mixing valve is the target mobile phase; When the injection time ends, the injection passage is controlled to be disconnected and the liquid phase passage is connected, so that the sample in the sample buffer component is pushed into the chromatographic column through the target mobile phase at the zero point of the liquid phase gradient.

8. The gradient elution control method according to claim 7, characterized in that: The injection time is calculated based on the sample suction time and the mechanical movement time, or calculated based on the sample suction time, the mechanical movement time and the cleaning time; wherein the sample suction time is the time taken by the injection needle of the injection device to suck up a sample each time, and the mechanical movement time is the time taken by the injection needle each time to push the injection needle to transfer the sample in the injection needle to the sample buffer component when the injection needle sucks up a sample; the cleaning time is the time taken to clean the injection needle; The delay volume time is calculated based on the flow velocity of the mobile phase in the mobile phase delivery component and the delay volume; wherein the delay volume is the spatial volume inside the gradient proportion mixing valve and the mobile phase delivery component, plus the sum of the volumes inside all pipelines between the gradient proportion mixing valve and the sample cache component.

9. The gradient elution control method according to claim 7, characterized in that: The control of the conduction of the injection path includes: Control the first interface and the second interface of the switching component to be connected, and the third interface and the fourth interface to be connected; The control liquid phase passage is connected to two interfaces other than the two interfaces connected to the sample cache component, including: The first interface and the sixth interface of the control switching component are disconnected, the fourth interface and the fifth interface are disconnected, and the fifth interface and the sixth interface are connected.

10. The gradient elution control method according to claim 7, characterized in that: The control of disconnecting the injection passage and connecting the liquid phase passage comprises: Control the first interface and the second interface of the switching component to be disconnected, and the third interface and the fourth interface to be disconnected; And control the first interface to be connected to the sixth interface, the fourth interface to be connected to the fifth interface, and the fifth interface to be disconnected from the sixth interface.

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