Chromatographic device and chromatographic analysis method

Abstract

The invention relates to a chromatographic device and a chromatographic analysis method.The chromatographic device comprises a chromatographic column, a sample injection valve, a sample injection assembly, a needle seat and a filtering unit, the sample injection assembly can selectively communicate with the needle seat, and the chromatographic device has a sample loading mode for supplying samples to the sample injection assembly and a sample injection mode for supplying samples to the chromatographic column; the sample injection valve is used for switching a sample injection mode and a sample loading mode, the sample injection valve at least comprises a first interface and a second interface, the chromatographic column is communicated with the first interface, and the needle seat is communicated with the second interface; in the sample loading mode, the first interface is disconnected from the second interface, so that the chromatographic column is disconnected from the needle seat, and the sample injection assembly is disconnected from the needle seat; in a sample introduction mode, the first interface is communicated with the second interface, so that the chromatographic column is communicated with the needle seat, the sample introduction assembly is communicated with the needle seat, and a sample can be transferred into the chromatographic column. The filtering unit is arranged on a flowing path between the needle seat and the second interface and is used for filtering a sample entering the sample injection valve, so that the sample injection valve is prevented from being blocked or abraded by impurities in the sample.

Description

Technical Field

[0001] The present application relates to the technical field of sample analysis, and in particular to a chromatographic device and a chromatographic analysis method. Background Art

[0002] Liquid chromatography is an important branch of chromatographic analysis. It refers to the technology of separating target analytes by using liquid as mobile phase. When the mobile phase (such as solvent, water, etc.) containing the sample passes through the stationary phase, the stationary phase will interact with the components in the sample, thereby achieving the separation of the components in the sample. The liquid chromatography system has strict requirements for sample pretreatment. Impurities in the sample may interfere with the separation efficiency of the liquid chromatography device and the signal response of the detector, and may wear and clog the chromatographic column or injection valve in the chromatographic device, thereby affecting the service life of the chromatographic column or injection valve. In some cases, such as in the process of extracting samples by magnetic beads, a large number of magnetic beads (with a diameter of tens of microns) are usually mixed in the sample. These magnetic beads can easily cause pipeline blockage, thereby shortening the service life of the chromatographic column or injection valve in the chromatographic device. The existing technology generally requires the sample to be centrifuged and filtered in a pretreatment manner before entering the chromatographic device, but these steps greatly increase the workload of the user. Summary of the invention

[0003] Based on this, the present application provides a chromatography device and a chromatography analysis method with online filtering function to simplify the centrifugation and filtration requirements before sample injection, and can protect the injection valve, chromatography column and other components in the chromatography device.

[0004] A chromatographic device comprises an injection valve, an injection assembly, a needle seat and a chromatographic column, wherein the injection assembly can be selectively connected to the needle seat, the chromatographic device has a loading mode for supplying a sample into the injection assembly and an injection mode for supplying a sample into the chromatographic column, and the injection valve can switch between the injection mode and the loading mode. The injection valve at least comprises a first interface and a second interface, the chromatographic column is communicated with the first interface, and the needle seat is communicated with the second interface; When the injection valve is in a loading mode, the first interface is disconnected from the second interface, so that the chromatographic column is disconnected from the needle seat, and the injection assembly is disconnected from the needle seat; When the injection valve is in the injection mode, the first interface is communicated with the second interface, so that the chromatographic column is communicated with the needle seat, the injection assembly is communicated with the needle seat, and the sample can be transferred from the injection assembly to the chromatographic column through the needle seat and the injection valve; The chromatographic device further comprises a filtering unit, and the filtering unit is arranged on the flow path between the needle seat and the second interface.

[0005] In one embodiment, the filter unit comprises a housing and a filter element, wherein the housing is provided with a first channel, a second channel and a filter cavity for accommodating the filter element. The first channel is connected to the filter cavity and the needle seat, and the second channel is connected to the filter cavity and the second interface; the first channel has an outlet connected to the filter cavity, and a gap is provided between the outlet and the filter element.

[0006] In one embodiment, the outlet is located above the filter element, and the height of the gap along the up and down direction is defined as H, 100 microns ≤ H ≤ 1000 microns.

[0007] In one embodiment, the outer shell includes a bottom shell and a cover body, the bottom shell and the cover body are connected and surround the filter cavity, and a limiting member is also provided in the filter cavity, and the limiting member is supported between the filter element and the cover body to press the filter element against the bottom shell.

[0008] In one embodiment, the cross section of the bottom shell is circular, the limiting member is annular, and the outer peripheral wall of the limiting member abuts against the inner peripheral wall of the bottom shell.

[0009] In one embodiment, the cross section of the filter element is circular, and the stopper is arranged at the edge of the filter element; And / or, the filter element is provided with filter holes, and the pore size of the filter holes is 0.2 microns to 0.5 microns; And / or, the filter element is circular, and the diameter of the filter element is 2 mm to 3.2 mm.

[0010] In one embodiment, the cover body and the limiting member are integrally formed.

[0011] In one embodiment, the injection assembly includes an injection part, an injection pump and a waste liquid collection part, the injection valve also includes a third interface, a fourth interface, a fifth interface and a sixth interface, and the chromatographic device also includes a solvent pump, wherein, The third interface is connected to the waste liquid collecting component. The fourth interface is connected to the injection pump, The fifth interface is connected to the sample injection part, and the sample injection part is used to temporarily store samples. The sixth interface is connected to the solvent pump, When the injection valve is in the loading mode, the first interface is connected to the sixth interface, the second interface is connected to the third interface, the fourth interface is connected to the fifth interface, and the first interface is disconnected from the second interface, the third interface is disconnected from the fourth interface, and the fifth interface is disconnected from the sixth interface. When the injection valve is in the injection mode, the third interface is connected to the fourth interface, the fifth interface is connected to the sixth interface, the first interface is disconnected from the sixth interface, the second interface is disconnected from the third interface, and the fourth interface is disconnected from the fifth interface.

[0012] In one embodiment, the chromatographic device further comprises a sample bottle for containing the sample, and the sample bottle is provided with a magnet for adsorbing magnetic substances in the sample. And when the injection valve is in a sample loading mode, the injection assembly is connected to the sample bottle.

[0013] The present application also provides a chromatographic analysis method of the chromatographic device as described in any of the above embodiments, wherein the method of use comprises the following contents: The injection valve is placed in a sample loading mode, and the sample enters the injection component and is temporarily stored in the injection component; Connecting the injection assembly to the needle seat; The injection valve is placed in an injection mode, and the sample flows from the injection assembly through the needle seat, the filter unit, and the injection valve in sequence, and is transferred to the chromatographic column; The connection between the injection assembly and the needle seat is disconnected, the injection valve is placed in a loading mode, and the sample is subjected to chromatographic separation.

[0014] Compared with the prior art, the chromatographic device provided in the present application, by arranging the filtering unit between the needle seat and the second interface, can perform online filtering on the sample entering the injection valve without filtering the sample in advance, which can not only prevent the impurities in the sample from clogging or wearing the injection valve, chromatographic column, etc., but also simplify the pretreatment steps before sample injection.

[0015] Since the prior art performs chromatographic separation on the sample in the chromatographic column in the injection mode, that is, the mobile phase can reach the chromatographic column only after passing through the injection assembly, therefore, the dead volume is calculated from the mobile phase outlet. However, the chromatographic analysis method based on the chromatographic device of the present application is that after the sample enters the injection valve, the injection valve switches from the injection mode to the loading mode, the injection assembly is disconnected from the needle seat, and the chromatographic device performs chromatographic separation on the sample in the loading mode, that is, the mobile phase can directly reach the chromatographic column without flowing through the injection assembly, that is, the flow path of the mobile phase becomes shorter, which also reduces the dead volume at the front end of the chromatographic column, and the chromatographic separation process is no longer affected by the addition of the filtration unit. The chromatographic separation or chromatographic peak shape will not be affected, and thus the analysis results will not be affected. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 This is a schematic structural diagram of a chromatographic device in a sample loading mode according to an embodiment of the present application; Figure 2 This is a schematic structural diagram of a chromatographic device in an injection mode according to an embodiment of the present application; Figure 3 Another structural schematic diagram of a chromatographic device in a sample loading mode according to an embodiment of the present application; Figure 4 It is a cross-sectional schematic diagram of a filter unit in one embodiment of the present application.

[0018] Reference numerals: 10. injection valve; 11. first interface; 12. second interface; 13. third interface; 14. fourth interface; 15. fifth interface; 16. sixth interface; 20. Sampling assembly; 21. Sampling part; 211. Sampling needle; 212. Sample quantitative loop; 22. Sampling pump; 23. Waste liquid collection part; 30. Needle holder; 40. Chromatographic column; 50, filter unit; 501, filter chamber; 502, first channel; 503, second channel; 504, outlet; 510, housing; 511, bottom housing; 512, cover; 520, filter element; 530, stopper; 60. Sample bottle; 70. Solvent pump. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0020] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0022] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediate medium. Moreover, a first feature being “above”, “above”, or “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, or “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0023] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more related listed items.

[0024] See also Figures 1 to 4The present application provides a chromatography device, including a chromatography column 40, an injection valve 10, an injection assembly 20 and a needle seat 30. The injection assembly 20 can be selectively connected to the needle seat 30. The chromatography device has a loading mode for supplying samples into the injection assembly 20 and an injection mode for supplying samples into the chromatography column 40. The injection valve 10 can switch the injection mode and the loading mode. The injection valve 10 includes at least a first interface 11 and a second interface 12. The chromatography column 40 is connected to the first interface 11, and the needle seat 30 is connected to the second interface 12.

[0025] like Figure 1 As shown, when the injection valve 10 is in the loading mode, the first interface 11 is disconnected from the second interface 12 , so that the chromatographic column 40 is disconnected from the needle seat 30 , and the injection assembly 20 is disconnected from the needle seat 30 .

[0026] like Figure 2 As shown, when the injection valve 10 is in the injection mode, the first interface 11 is connected to the second interface 12, so that the chromatographic column 40 is connected to the needle seat 30, and the injection assembly 20 is connected to the needle seat 30, and the sample can be transferred from the injection assembly 20 to the chromatographic column 40 through the needle seat 30 and the injection valve 10.

[0027] The above-mentioned chromatographic device also includes a filtering unit 50, and the filtering unit 50 is arranged on the flow path between the needle seat 30 and the second interface 12. By arranging the filtering unit 50 between the needle seat 30 and the second interface 12, the sample entering the injection valve 10 can be filtered online. When using the chromatographic device, since the chromatographic device does not need to filter the sample in advance, the workload of the user is reduced. And relative to the chromatographic device that needs to be filtered in advance, if the user omits the filtering step, the impurities and magnetic beads in the sample will damage the injection valve and the chromatographic column. This embodiment can avoid this situation and prevent the impurities in the sample from clogging or wearing the injection valve 10. Further, filtering the sample entering the injection valve 10, that is, filtering the sample entering the chromatographic column 40, therefore, it is also possible to avoid the impurities in the sample from clogging or wearing the chromatographic column 40, thereby preventing the injection valve 10 and the chromatographic column 40 from being damaged.

[0028] It should be noted that the online filtration of the sample means that the chromatographic device in this embodiment can automatically and continuously transport the sample to the injection assembly 20, and transport the sample from the injection assembly 20 to the chromatographic column 40 through the needle seat 30, the filter unit 50, and the injection valve 10 in sequence, and then separate the components in the sample in the chromatographic column 40 and transport them to the detector located downstream of the chromatographic column 40 for direct detection. During the flow transportation and transfer of the sample, the chromatographic device can operate continuously without interruption due to the filtration process of the filter unit 50. Therefore, the chromatographic device in this embodiment can improve the processing speed of the sample by the chromatographic device on the basis of being able to filter online, and the chromatographic device is simple to operate, highly automated, and saves manpower.

[0029] Further, the chromatographic device also includes a sample bottle 60, an injection pump 22 and a solvent pump 70, wherein the sample bottle 60 is used to contain and supply a sample. The injection assembly 20 includes at least an injection needle 211 and a sample quantitative ring 212, in which a certain volume of sample can be stored, one end of the injection needle 211 is connected to the sample quantitative ring 212, and the other end of the injection needle 211 is used to selectively communicate with the sample bottle 60 or the needle seat 30. The injection pump 22 is used to drive the sample from the sample bottle 60 through the injection needle 211 into the sample quantitative ring 212, the solvent pump 70 is used to drive the sample from the sample quantitative ring 212 to flow through the injection needle 211, the needle seat 30, and the injection valve 10 into the chromatographic column 40 in sequence, and the solvent pump 70 is also used to drive the mobile phase and the sample in the chromatographic column 40 to flow in the chromatographic column 40.

[0030] The working principle of the above chromatographic device is: First, if Figure 1 As shown, the injection valve 10 is switched to the sample loading mode, and at the same time, the injection needle 211 is connected to the sample bottle 60, and under the action of the injection pump 22, the sample enters the sample quantitative loop 212; Secondly, if Figure 2 As shown, the injection valve 10 is switched to the injection mode, and at the same time, the injection needle 211 is connected to the needle seat 30, and the first interface 11 is connected to the second interface 12, so that the chromatographic column 40 is connected to the needle seat 30. Under the action of the solvent pump 70, the sample leaves the sample quantitative loop 212, flows through the injection needle 211, the needle seat 30, and the injection valve 10 in sequence, and then enters the chromatographic column 40; Finally, if Figure 3 As shown, the injection valve 10 is switched to the loading mode, and the solvent pump 70 drives the mobile phase and the sample in the chromatographic column 40 to flow in the chromatographic column 40, thereby completing the separation of the target analyte in the sample.

[0031] It should be noted that the above-mentioned "connection" means that the fluid can flow between two components. It is understandable that the injection needle 211 and the sample quantitative loop 212, the sample quantitative loop 212 and the injection pump 22, the injection valve 10 and the chromatographic column 40, the injection valve 10 and the filter unit 50, and the filter unit 50 and the needle seat 30 are only connected by pipelines as necessary, so that the above-mentioned components can be sealed and connected. Since it is common knowledge to connect components through pipelines so that the fluid can flow between two components, this application will not describe this any more.

[0032] It is understandable that the separation degree is an important indicator of the chromatographic device, which is used to measure the separation of adjacent elution components. It is a parameter that combines the chromatographic separation efficiency and the mobile phase efficiency. The greater the separation degree, the better the separation of two adjacent elution components. The dead volume of the chromatographic device is an important factor affecting the separation degree. The dead volume originally refers to the void volume in the chromatographic column 40 that is not occupied by the stationary phase, that is, the volume of the mobile phase in the chromatographic column 40. However, in actual measurement, the dead volume refers to the volume of the section from the injection position (injection port) to the detection position (chromatographic detector flow cell, for the liquid chromatography-mass spectrometry tandem system, the detection position refers to the ion source inlet of the mass spectrometer) (excluding the volume of the filler in the chromatographic column), that is, the dead volume includes the following four parts: the volume from the mobile phase outlet 504 to the front end of the chromatographic column 40, the gap between the stationary phases in the chromatographic column 40, the pipeline volume of the chromatographic column 40 outlet 504, and the volume in the detector of the chromatographic device, because once the chromatographic column is connected, this section of volume is unchanged (dead). The larger the dead volume, the larger the space for sample diffusion, which will lead to poor sample separation, poor chromatographic peak shape (such as broad peaks or tailing peaks), resolution loss, etc., which will affect the analysis results and make the chromatographic performance worse. At the same time, the dead volume will also cause the chromatographic peak to elute at a delayed time and increase the chromatographic separation time. It should be emphasized that adding components (such as the filter unit 50), unnecessary pipes, connectors, etc. to the chromatographic device will introduce dead volume into the chromatographic device. However, since the portion other than the injection port of the injection assembly 20 to the front end of the chromatographic column 40 in the chromatographic device is not modified in this embodiment, in this embodiment, the "dead volume" refers to the volume between the "injection port of the injection assembly 20" and the front end of the chromatographic column 40.

[0033] Since the prior art performs chromatographic separation on the sample in the chromatographic column 40 in the injection mode, that is, the mobile phase can enter the chromatographic column 40 to perform chromatographic separation on the sample only after passing through the mobile phase outlet 504, the injection assembly 20, the filter unit 50, and the injection valve 10 in sequence, so the dead volume in the prior art can be calculated from the injection port of the injection assembly 20. In this embodiment, after the sample enters the injection valve 10, the injection valve 10 is switched from the injection mode to the loading mode, the injection assembly 20 is disconnected from the needle seat 30, and the chromatographic device performs chromatographic separation on the sample in the loading mode, that is, the mobile phase directly enters the chromatographic column 40, instead of entering the chromatographic column 40 after passing through the injection assembly 20, the filter unit 50, and the injection valve 10. Therefore, at this time, the dead volume is calculated from the needle seat 30, which is equivalent to reducing the dead volume at the front end of the chromatographic column 40, and the chromatographic separation process is no longer affected by the addition of the filter unit 50. The chromatographic separation or chromatographic peak shape will not be affected, and the analysis results will not be affected.

[0034] It can be understood that the chromatographic device also includes a mobile phase supply component, which is connected to the above-mentioned solvent pump 70, and the mobile phase can flow from the mobile phase supply component into the adapter assembly or the chromatographic column 40 under the drive of the solvent pump 70. The above-mentioned mobile phase outlet 504 is the outlet 504 of the mobile phase supply component.

[0035] In one embodiment, the filter unit 50 includes a housing 510 and a filter element 520, wherein the housing 510 is provided with a first channel 502, a second channel 503, and a filter cavity 501 for accommodating the filter element 520. The first channel 502 is connected to the filter cavity 501 and the needle seat 30, and the second channel 503 is connected to the filter cavity 501 and the second interface 12; the first channel 502 has an outlet 504 connected to the filter cavity 501, and a gap is provided between the outlet 504 and the filter element 520. In this way, the effective filtering area of ​​the filter sheet can be expanded.

[0036] It is understandable that if there is no gap between the outlet and the filter element, that is, the outlet is close to the filter element, the contact surface between the sample and the filter element is the cross-section of the sample flowing out of the outlet. At this time, the effective filtration area of ​​the filter element is determined by the cross-sectional area of ​​the outlet. Taking the outlet as a circle with a diameter of 0.2mm as an example to calculate the effective filtration area of ​​the filter element, the effective filtration area of ​​the filter element is (0.1²π) mm², and the particles in the sample will be blocked at the junction of the outlet and the filter element, reducing the service life of the filter element. However, in this embodiment, if Figure 4 As shown, there is a gap between the outlet 504 and the filter element 520. After the sample flows out of the outlet 504, there is a diffusion process in the filter cavity, such as Figure 4As shown by the dotted line in the middle, the contact area between the sample and the filter element 520 is increased. At this time, the effective filtration area of ​​the filter element 520 is determined by the actual size of the filter element 520. Taking the filter element 520 as a circular shape and the diameter of the filter element 520 as an example, the effective filtration area of ​​the filter element 520 is calculated as π mm². In other words, the effective filtration area in this embodiment can be increased by 100 times, thereby extending the service life of the filter element 520.

[0037] The number of injections and the system pressure were tested. If a traditional filter unit (i.e., no gap between the outlet and the filter element) was used, the system pressure of the chromatographic device would exceed 15,000 psi after 300 injections and could no longer be used. However, after using the filter unit 50 in this embodiment, even after 3,000 injections, the system pressure of the chromatographic device was only 7,500 psi, and the filter unit 50 could still be used. It should be noted that, except for whether there is a gap between the outlet of the filter unit and the filter element, the other structures of the chromatographic device are the same, the injection method is the chromatographic analysis method of the chromatographic device described below, and the system pressure test method is a conventional method, which will not be described in detail here.

[0038] Furthermore, the present application does not limit the shape and cross-sectional area of ​​the filter element, as long as the filter element can match the filter cavity 501 or the bottom shell 511. It can also be understood that the filter element is provided with a filter hole, and the present application does not limit the pore size of the filter hole, as long as it can filter impurities in the sample and does not affect the flow of the target analyte. In addition, the specific value of the gap can be reasonably set according to the use requirements, and the present application does not limit the range of the gap.

[0039] In one embodiment, the outlet 504 is located above the filter element 520, and the height of the gap along the up and down direction is defined as H, 100μm≤H≤1000μm. If H is less than 100μm, the distance between the outlet 504 and the filter element 520 is too close, which may affect the diffusion process of the sample in the filter, reduce the effective filtration area of ​​the filter element 520, and thus make the actual size of the filter element 520 not fully utilized; if H is greater than 1000μm, the flow path between the needle seat 30 and the second interface 12 is extended, which will bring the risk of increasing the dead volume in the chromatographic device. Therefore, it is more appropriate to set H between 100μm and 1000μm. In this way, by increasing the distance between the outlet 504 and the filter element 520, the effective filtration area of ​​the filter plate is expanded.

[0040] It should be explained that the “above” here means that the outlet 504 is located upstream of the filter element 520 in the flow path between the needle seat 30 and the second interface 12, and is not limited to “above” in the direction of gravity.

[0041] Preferably, H is 500 μm, so that the distance between the outlet 504 and the second interface 12 is appropriate, which will neither affect the flow path between the needle seat 30 and the second interface 12 nor make the outlet 504 too close to the filter element 520, thereby expanding the effective filtering area of ​​the filter plate.

[0042] Illustratively, H may also be 100 μm, 200 μm, 300 μm, 400 μm, 600 μm, 700 μm, 900 μm, 800 μm, 1000 μm, or any other value within the range of 100 μm≤H≤1000 μm.

[0043] In one embodiment, the housing 510 includes a bottom shell 511 and a cover body 512, the bottom shell 511 and the cover body 512 are connected and surround a filter chamber 501, and a stopper 530 is further provided in the filter chamber 501, and the stopper 530 is held between the filter element 520 and the cover body 512 to press the filter element 520 against the bottom shell 511. The stopper 530 allows the filter element 520 and the cover body 512 to maintain a stable distance, so that the gap H is more stable, so that the filtering effect of the filter element 520 can be further guaranteed and the service life of the filter element 520 can be further extended.

[0044] In one embodiment, the cross section of the bottom shell 511 is circular, the stopper 530 is annular, and the outer peripheral wall of the stopper 530 abuts against the inner peripheral wall of the bottom shell 511. In this way, it is possible to prevent the stopper 530 from occupying too much surface area of ​​the filter element 520, thereby affecting the effective filtering area of ​​the filter element 520.

[0045] Furthermore, the cross section of the filter element 520 is circular, and the stopper 530 is disposed at the edge of the filter element 520. In this way, it is possible to prevent the stopper 530 from occupying too much surface area of ​​the filter element 520, thereby affecting the effective filtering area of ​​the filter element 520.

[0046] In one embodiment, the filter element 520 is provided with filter holes, and the pore size of the filter holes is 0.2 μm to 0.5 μm. In this way, the flow rate of the sample will not be affected due to the filter hole being too small, and the impurities in the sample can be effectively filtered.

[0047] Furthermore, the filter element 520 is circular, and the diameter of the filter element 520 is 2 mm to 3.2 mm. It is understandable that if the diameter of the filter element 520 is less than 2 mm, it is equivalent to reducing the effective filtering area of ​​the filter element 520. If the diameter of the filter element 520 is greater than 3.2 mm, the volume of the filter unit 50 is increased, which increases the difficulty of the sample flowing into the second channel 503, and may cause sample loss, affecting the analysis results. Therefore, it is more appropriate for the diameter of the filter element 520 to be 2 mm to 3.2 mm, so that the effective filtering area of ​​the filter element 520 can be increased without increasing the volume of the filter unit 50.

[0048] Illustratively, the diameter of the filter element 520 may be 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3 mm, or a range consisting of any two of these values.

[0049] In one embodiment, the cover 512 and the stopper 530 are integrally formed. Thus, when replacing the filter element 520, the stopper 530 is removed while the cover 512 is removed, and there is no need to remove and install the stopper 530 separately, which saves the step of replacing the filter element 520 and avoids the risk of losing the stopper 530 during the process of replacing the filter element 520.

[0050] In one embodiment, the injection assembly 20 includes an injection part 21, an injection pump 22 and a waste liquid collection part 23, and the injection part 21 includes the above-mentioned injection needle 211 and a sample quantitative loop 212. The injection valve 10 also includes a third interface 13, a fourth interface 14, a fifth interface 15 and a sixth interface 16. The chromatographic device also includes a solvent pump 70, wherein the third interface 13 is connected to the waste liquid collection part 23, the fourth interface 14 is connected to the injection pump 22, the fifth interface 15 is connected to the injection needle 211 in the injection part 21, the sample quantitative loop 212 in the injection part 21 is used for temporarily storing samples, and the injection needle 211 in the injection part 21 is used for selective connection with the sample bottle 60 or the needle seat 30, so that the sample flows from the sample bottle 60 into the sample quantitative bottle or from the sample quantitative loop 212 into the needle seat 30, and the sixth interface 16 is connected to the solvent pump 70. It should be noted that the injection pump 22 is used to drive the sample from the sample bottle 60 into the sample quantitative loop 212 of the injection part 21. When the injection valve 10 is in the injection mode, the solvent pump 70 is used to drive the sample from the sample quantitative loop 212 to flow through the injection needle 211, the needle seat 30, the injection valve 10 and into the chromatographic column 40 in sequence. When the injection valve 10 is in the loading mode, the solvent pump 70 is also used to drive the mobile phase or the sample in the chromatographic column 40 to flow in the chromatographic column 40. It can be understood that when the injection valve 10 is in the loading mode, after the sample enters the sample quantitative loop 212, due to the limited volume of the sample quantitative loop 212, the excess sample will be discharged from the outlet 504 of the sample quantitative loop 212 in the form of waste liquid. The waste liquid collection member 23 is used to collect the waste liquid discharged from the sample quantitative loop 212.

[0051] When the injection valve 10 is in the loading mode, the first interface 11 is connected to the sixth interface 16, the second interface 12 is connected to the third interface 13, the fourth interface 14 is connected to the fifth interface 15, and the first interface 11 is disconnected from the second interface 12, the third interface 13 is disconnected from the fourth interface 14, and the fifth interface 15 is disconnected from the sixth interface 16. It can be understood that at this time, driven by the injection pump 22, the flow path of the sample is: from the sample bottle 60 through the injection needle 211 into the sample quantitative loop 212, Figure 1The arrows in the figure indicate the flow path of the sample.

[0052] When the injection valve 10 is in the injection mode, the third interface 13 is connected to the fourth interface 14, the fifth interface 15 is connected to the sixth interface 16, and the first interface 11 is disconnected from the sixth interface 16, the second interface 12 is disconnected from the third interface 13, and the fourth interface 14 is disconnected from the fifth interface 15. It can be understood that after the sample has entered the sample quantitative loop 212 of the injection part 21 from the sample bottle 60, the injection needle 211 of the injection part 21 is connected to the needle seat 30. At this time, under the drive of the solvent pump 70, the flow path of the sample is: after flowing from the sample quantitative loop 212 through the injection needle 211 and the needle seat 30, it flows into the sample valve from the second interface 12 of the sample valve connected to the needle seat 30, and flows out of the sample valve from the first interface 11 of the sample valve, and then flows into the chromatographic column 40. Figure 2 The arrows in the figure indicate the flow path of the sample.

[0053] It should also be emphasized that when the sample flows out of the chromatographic column 40, the sample valve can be switched from the injection mode to the loading mode. At this time, the sample is still driven by the solvent pump 70, and the sample is chromatographically separated in the chromatographic column 40, and the final separated target analyte flows out from the outlet 504 of the chromatographic column 40.

[0054] In this way, the automatic injection and chromatographic separation of the sample can be completed, and the structure of the chromatographic device can be simplified. Schematically, the injection valve 10 is a six-way valve, which has the above-mentioned six interfaces at the same time and can also switch between the injection mode and the loading mode. In other embodiments, the injection valve 10 can also use a ten-way valve or other valves, and the present application does not limit this.

[0055] In one embodiment, the chromatographic device also includes a sample bottle 60 for accommodating the sample, and the sample bottle 60 is provided with a magnet for adsorbing the magnetic substance in the sample, and when the injection valve 10 is in the loading mode, the injection assembly 20 is connected to the sample bottle 60. It is understandable that when the sample is pretreated using the magnetic bead method, some magnetic substances such as magnetic beads and magnetic bead fragments will remain in the sample. By arranging a magnet on the sample bottle 60, this embodiment can make the magnetic substance remaining in the sample close to the magnet and be stably adsorbed on the inner wall of the sample bottle 60, thereby preventing the magnetic substance from entering the injection assembly 20, preventing the magnetic substance from entering the injection valve 10, and thus avoiding clogging or wear of the injection valve 10.

[0056] Furthermore, the magnet can be arranged on the side of the sample bottle 60 or on the bottom of the sample bottle 60, and the present application does not limit this, as long as the magnet can absorb the magnetic substance in the sample. Similarly, the number of magnets can be set according to the situation, and the present application does not limit this.

[0057] The present application also provides a chromatographic analysis method of the chromatographic device in any of the above embodiments, the chromatographic analysis method comprising the following contents: S1: The injection valve 10 is placed in a sample loading mode, and the sample enters the injection component 20 and is temporarily stored in the injection component 20; S2: Connecting the injection assembly 20 and the needle seat 30; S3: The injection valve 10 is placed in the injection mode, and the sample flows from the injection assembly 20 through the needle seat 30, the filter unit 50, the injection valve 10 in sequence, and is transferred to the chromatographic column 40; S4: disconnect the connection between the injection assembly 20 and the needle seat 30, put the injection valve 10 in the loading mode, and perform chromatographic separation on the sample.

[0058] It is understandable that, in the process of the sample being transported from the injection assembly 20 to the chromatographic column 40 and undergoing chromatographic separation in the chromatographic column 40, the injection assembly 20, the needle seat 30, the filter unit 50 and the chromatographic column 40 can be separated by switching the injection valve 10 from the injection mode to the loading mode. In this way, the influence of the dead volume on the chromatographic separation is eliminated in the process of the sample undergoing chromatographic separation in the chromatographic column 40. The injection assembly 20 can then be separated from the needle seat 30 for cleaning or extracting a new sample, so as to prepare for the next injection and loading.

[0059] Compared with the prior art (in which no filter unit is provided between the second interface of the injection valve and the needle seat), the chromatographic device and chromatographic analysis method provided in the present application have no adverse effects on the separation effect and signal response of the target analyte in the sample. In other words, the provision of a filter unit between the second interface of the injection valve and the needle seat has no obvious adverse effect on the chromatographic fraction. For occasions in which there are strict requirements on the volume before the chromatographic column in the chromatographic device, the problem of a large volume before the chromatographic column can be avoided by the chromatographic analysis method based on the chromatographic device in the present application.

[0060] The filtration unit of the chromatographic device of the present application can effectively filter large impurities in the sample, prevent the sample from clogging or wearing the injection valve and the chromatographic column, and can extend the service life of the pipeline, injection valve and chromatographic column of the chromatographic device, thereby saving costs. In particular, when the magnetic bead method is used to pretreat the sample, magnetic substances such as magnetic beads and impurities can be effectively removed.

[0061] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0062] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of patent protection of the present application shall be subject to the attached claims.

Claims

1. A chromatographic device, comprising an injection valve (10), an injection assembly (20), a needle seat (30) and a chromatographic column (40), wherein the injection assembly (20) can be selectively connected to the needle seat (30), the chromatographic device has a loading mode for supplying a sample into the injection assembly (20) and an injection mode for supplying a sample into the chromatographic column (40), and the injection valve (10) can switch between the injection mode and the loading mode. The injection valve (10) comprises at least a first interface (11) and a second interface (12), the chromatographic column (40) is in communication with the first interface (11), and the needle seat (30) is in communication with the second interface (12); When the injection valve (10) is in a loading mode, the first interface (11) is disconnected from the second interface (12), so that the chromatographic column (40) is disconnected from the needle seat (30), and the injection assembly (20) is disconnected from the needle seat (30); When the injection valve (10) is in an injection mode, the first interface (11) is in communication with the second interface (12), so that the chromatographic column (40) is in communication with the needle seat (30), and the injection assembly (20) is in communication with the needle seat (30), so that the sample can be transferred from the injection assembly (20) to the chromatographic column (40) via the needle seat (30) and the injection valve (10); It is characterized in that The chromatographic device further comprises a filtering unit (50), wherein the filtering unit (50) is arranged on the flow path between the needle seat (30) and the second interface (12).

2. The chromatographic device according to claim 1, characterized in that The filter unit (50) comprises a housing (510) and a filter element (520); the housing (510) is provided with a first channel (502), a second channel (503), and a filter cavity (501) for accommodating the filter element (520). The first channel (502) is in communication with the filter cavity (501) and the needle seat (30), and the second channel (503) is in communication with the filter cavity (501) and the second interface (12); the first channel (502) has an outlet (504) in communication with the filter cavity (501), and a gap is provided between the outlet (504) and the filter element (520).

3. The chromatographic device according to claim 2, characterized in that The outlet (504) is located above the filter element (520), and the height of the gap along the vertical direction is defined as H, 100 microns ≤ H ≤ 1000 microns.

4. The chromatographic device according to claim 2, characterized in that The housing (510) comprises a bottom shell (511) and a cover body (512); the bottom shell (511) and the cover body (512) are connected to and surround the filter cavity (501); a limiting member (530) is further provided in the filter cavity (501); the limiting member (530) is abutted between the filter element (520) and the cover body (512) so as to press the filter element (520) against the bottom shell (511).

5. The chromatographic device according to claim 4, characterized in that The cross section of the bottom shell (511) is circular, the limiting member (530) is ring-shaped, and the outer peripheral wall of the limiting member (530) abuts against the inner peripheral wall of the bottom shell (511).

6. The chromatographic device according to claim 5, characterized in that The cross section of the filter element (520) is circular, and the limiting member (530) is arranged at the edge of the filter element (520); And / or, the filter element (520) is provided with filter holes, and the pore size of the filter holes is 0.2 micrometers to 0.5 micrometers; And / or, the filter element (520) is circular, and the diameter of the filter element (520) is 2 mm to 3.2 mm.

7. The chromatographic device according to claim 4, characterized in that The cover body (512) and the limiting component (530) are integrally formed.

8. The chromatographic device according to claim 1, characterized in that The injection assembly (20) comprises an injection part (21), an injection pump (22) and a waste liquid collection part (23); the injection valve (10) further comprises a third interface (13), a fourth interface (14), a fifth interface (15) and a sixth interface (16); the chromatographic device further comprises a solvent pump (70), wherein: The third interface (13) is in communication with the waste liquid collecting member (23). The fourth interface (14) is in communication with the injection pump (22). The fifth interface (15) is in communication with the sample injection part (21), and the sample injection part (21) is used for temporarily storing samples. The sixth interface (16) is in communication with the solvent pump (70). When the injection valve (10) is in a loading mode, the first interface (11) is in communication with the sixth interface (16), the second interface (12) is in communication with the third interface (13), the fourth interface (14) is in communication with the fifth interface (15), and the first interface (11) is disconnected from the second interface (12), the third interface (13) is disconnected from the fourth interface (14), and the fifth interface (15) is disconnected from the sixth interface (16). When the injection valve (10) is in the injection mode, the third interface (13) is connected to the fourth interface (14), the fifth interface (15) is connected to the sixth interface (16), and the first interface (11) is disconnected from the sixth interface (16), the second interface (12) is disconnected from the third interface (13), and the fourth interface (14) is disconnected from the fifth interface (15).

9. The chromatographic device according to any one of claims 1 to 8, characterized in that The chromatographic device further comprises a sample bottle (60) for containing the sample, wherein the sample bottle (60) is provided with a magnet for adsorbing magnetic substances in the sample. Furthermore, when the injection valve (10) is in a sample loading mode, the injection assembly (20) is connected to the sample bottle (60).

10. A chromatographic analysis method according to any one of claims 1 to 9, characterized in that: The chromatographic analysis method comprises the following contents: The injection valve is placed in a sample loading mode, and the sample enters the injection component and is temporarily stored in the injection component; Connecting the injection assembly to the needle seat; The injection valve is placed in an injection mode, and the sample flows from the injection assembly through the needle seat, the filter unit, and the injection valve in sequence, and is transferred to the chromatographic column; The connection between the injection assembly and the needle seat is disconnected, the injection valve is placed in a loading mode, and the sample is subjected to chromatographic separation.

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