Chromatographic device and chromatographic analysis method

Abstract

The present application relates to a chromatographic device and a chromatographic analysis method, wherein the chromatographic device includes a chromatographic column, an injection valve, an injection assembly, a needle seat and a filter unit, wherein the injection assembly can selectively communicate with the needle seat, and the chromatographic device has a loading mode for supplying a sample to the injection assembly and an injection mode for supplying a sample to the chromatographic column, wherein the injection valve is used to switch between the injection mode and the loading mode, and the injection valve includes at least a first interface and a second interface, wherein the chromatographic column is connected to the first interface and the needle seat is connected to the second interface; in the 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; in the injection mode, the first interface is connected to the second interface so that the chromatographic column is connected to the needle seat and the injection assembly is connected to the needle seat, and the sample can be transferred to the chromatographic column. The filter unit is arranged on the flow path between the needle seat and the second interface to filter the sample entering the injection valve to prevent impurities in the sample from clogging or wearing the injection valve.

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, a key branch of chromatographic analysis, uses a liquid as the mobile phase to separate target analytes. When the mobile phase (e.g., solvent, water, etc.) containing the sample passes through a stationary phase, it interacts with the sample components, achieving separation. Liquid chromatography systems impose stringent requirements on sample pretreatment. Impurities in the sample can interfere with the separation efficiency and detector signal response of the liquid chromatography device and can also wear and clog the chromatographic column or injection valve, thereby reducing their service life. In some cases, such as during sample extraction using magnetic beads, large quantities of magnetic beads (tens of microns in diameter) are often present in the sample. These beads can easily clog the pipeline, shortening the service life of the chromatographic column or injection valve. Existing techniques generally require pretreatment by centrifugation and filtration before the sample enters the chromatographic device. However, these steps significantly increase the user's workload. Summary of the Invention

[0003] Based on this, the present application provides a chromatography device and a chromatography analysis method with online filtration 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 selectively communicate with the needle seat, the chromatographic device has a loading mode for supplying a sample into the injection assembly and a sampling mode for supplying a sample into the chromatographic column, and the injection valve can switch between the loading mode and the sampling mode.

[0005] The injection valve comprises at least 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;

[0006] 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;

[0007] When the injection valve is in injection mode, the first interface is in communication with the second interface, so that the chromatographic column is in communication with the needle seat, and the injection assembly is in communication with the needle seat, so that the sample can be transferred from the injection assembly through the needle seat and the injection valve to the chromatographic column;

[0008] The chromatographic device further comprises a filtration unit, which is arranged on the flow path between the needle seat and the second interface.

[0009] In one embodiment, the filter unit includes 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.

[0010] 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.

[0011] In one embodiment, the outlet is located above the filter element, and the height of the gap along the vertical direction is defined as H, 100 microns ≤ H ≤ 1000 microns.

[0012] In one embodiment, the outer shell includes a bottom shell and a cover body, the bottom shell and the cover body are connected and enclose 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.

[0013] 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.

[0014] In one embodiment, the cross section of the filter element is circular, and the limiting member is provided at the edge of the filter element;

[0015] 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;

[0016] And / or, the filter element is circular, and the diameter of the filter element is 2 mm to 3.2 mm.

[0017] In one embodiment, the cover and the limiting member are integrally formed.

[0018] 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,

[0019] The third interface is connected to the waste liquid collection component,

[0020] The fourth interface is connected to the injection pump,

[0021] The fifth interface is connected to the sample injection part, and the sample injection part is used to temporarily store samples.

[0022] The sixth interface is connected to the solvent pump,

[0023] 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, and 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.

[0024] 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.

[0025] In one embodiment, the chromatography 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.

[0026] When the injection valve is in a sample loading mode, the injection assembly is connected to the sample bottle.

[0027] The present application also provides a chromatographic analysis method of the chromatographic device according to any of the above embodiments, wherein the method of using the chromatographic device comprises the following contents:

[0028] 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;

[0029] connecting the injection assembly and the needle seat;

[0030] The injection valve is placed in an injection mode, and the sample flows from the injection assembly through the needle seat, the filter unit, the injection valve in sequence, and is transferred to the chromatographic column;

[0031] The connection between the injection assembly and the needle seat is disconnected, the injection valve is placed in a sample loading mode, and the sample is subjected to chromatographic separation.

[0032] Compared with the prior art, the chromatographic device provided in the present application can perform online filtration on the sample entering the injection valve by arranging the filtration unit between the needle seat and the second interface, without filtering the sample in advance. This not only prevents impurities in the sample from clogging or wearing the injection valve, chromatographic column, etc., but also simplifies the pretreatment steps before sample injection.

[0033] Since the prior art performs chromatographic separation on the sample in the chromatographic column in the injection mode, that is, the mobile phase can only reach the chromatographic column after passing through the injection assembly, 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 does not need to flow through the injection assembly and can directly reach the chromatographic column, that is, the flow path of the mobile phase becomes shorter, thereby reducing the dead volume at the front end of the chromatographic column. The chromatographic separation process will no longer be affected by the addition of a filter 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

[0034] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following is a brief introduction to the drawings required for use in the embodiments or the conventional technology descriptions. 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.

[0035] Figure 1 This is a schematic structural diagram of a chromatography device in a sample loading mode according to an embodiment of the present application;

[0036] Figure 2 This is a schematic structural diagram of a chromatographic device in an injection mode according to an embodiment of the present application;

[0037] Figure 3 This is another structural schematic diagram of the chromatography device in one embodiment of the present application in the sample loading mode;

[0038] Figure 4 Schematic cross-sectional view of a filter unit in one embodiment of the present application.

[0039] Reference numerals:

[0040] 10. Injection valve; 11. First interface; 12. Second interface; 13. Third interface; 14. Fourth interface; 15. Fifth interface; 16. Sixth interface;

[0041] 20. Injection assembly; 21. Injection piece; 211. Injection needle; 212. Sample loop; 22. Injection pump; 23. Waste liquid collection piece;

[0042] 30. Needle holder;

[0043] 40. Chromatographic column;

[0044] 50. Filter unit; 501. Filter chamber; 502. First channel; 503. Second channel; 504. Outlet; 510. Housing; 511. Bottom shell; 512. Cover; 520. Filter element; 530. Stopper;

[0045] 60. Sample bottle; 70. Solvent pump. DETAILED DESCRIPTION

[0046] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0047] 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.

[0048] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, features specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0049] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it can 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 intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it can mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is higher in level than the second feature. When a first feature is "below," "below," or "below" a second feature, it can mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is lower in level than the second feature.

[0050] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as 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 of the relevant listed items.

[0051] See Figures 1 to 4 The 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 between 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.

[0052] 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 .

[0053] 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 through the needle seat 30 and the injection valve 10 to the chromatographic column 40.

[0054] The above-mentioned chromatographic device also includes a filter unit 50, which is arranged on the flow path between the needle seat 30 and the second interface 12. By arranging the filter 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 compared with 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. The present embodiment can avoid this situation and prevent the impurities in the sample from clogging or wearing the injection valve 10. Furthermore, the sample entering the injection valve 10 is filtered, that is, the sample entering the chromatographic column 40 is filtered. Therefore, it is also possible to prevent the impurities in the sample from clogging or wearing the chromatographic column 40, thereby preventing the damage to the injection valve 10 and the chromatographic column 40.

[0055] It should be noted that online filtration of a sample means that the chromatographic device in this embodiment can automatically and continuously transport the sample from the injection assembly 20, and then 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. The components in the sample are then separated in the chromatographic column 40 and transported to a detector located downstream of the chromatographic column 40 for direct detection. During the flow and transportation 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, while capable of online filtration, can increase the sample processing speed of the chromatographic device. The chromatographic device is also simple to operate, highly automated, and labor-saving.

[0056] Furthermore, 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 accommodate and supply a sample. The injection assembly 20 includes at least an injection needle 211 and a sample loop 212. The sample loop 212 can store a certain volume of sample. One end of the injection needle 211 is connected to the sample loop 212, and the other end of the injection needle 211 is used to selectively connect to 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 loop 212. The solvent pump 70 is used to drive the sample from the sample loop 212 to flow through the injection needle 211, the needle seat 30, and the injection valve 10 into the chromatographic column 40. 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.

[0057] The working principle of the above chromatographic device is:

[0058] 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;

[0059] Secondly, if Figure 2 As shown, the injection valve 10 is switched to the injection mode. 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 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.

[0060] Finally, if Figure 3 As shown, the injection valve 10 is switched to the sample 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.

[0061] It should be noted that the aforementioned "connectivity" refers to the ability of fluid to flow between two components. It is understood that the injection needle 211 and the sample loop 212, the sample loop 212 and the injection pump 22, the injection valve 10 and the chromatographic column 40, the injection valve 10 and the filtration unit 50, and the filtration unit 50 and the needle seat 30 are all connected only by necessary pipes to achieve a sealed connection and connectivity between the aforementioned components. Since connecting components via pipes to enable fluid to flow between two components is common knowledge, this application will not further describe this.

[0062] It is understood that resolution is an important indicator of a chromatographic device, used to measure the separation of adjacent eluting components. It is a parameter that integrates chromatographic separation efficiency and mobile phase efficiency. The greater the resolution, the better the separation of two adjacent eluting components. The dead volume of a chromatographic device is also a significant factor influencing resolution. Originally, dead volume refers to the void volume in the chromatographic column 40 not occupied by the stationary phase, that is, the volume of the mobile phase within the chromatographic column 40. However, in actual measurements, dead volume refers to the volume between the injection point (inlet) and the detection point (chromatographic detector flow cell; for liquid chromatography-mass spectrometry tandem systems, the detection point refers to the ion source inlet of the mass spectrometer) (excluding the volume of the packing in the chromatographic column). In other words, dead volume consists of four components: the volume from the mobile phase outlet 504 to the front end of the chromatographic column 40, the gap between the stationary phase within the chromatographic column 40, the volume of the tubing at the outlet 504 of the chromatographic column 40, and the volume within the detector of the chromatographic device. This volume remains unchanged (dead) once the chromatographic column is connected. The larger the dead volume, the more space the sample has to diffuse, which can lead to poor sample separation, deteriorated chromatographic peak shape (e.g., broad or tailing peaks), and loss of resolution, thereby affecting analytical results and worsening chromatographic performance. At the same time, dead volume can also delay the chromatographic peak ejaculation time, increasing chromatographic separation time. It should be emphasized that adding components (e.g., filter unit 50), unnecessary piping, connectors, etc. to a chromatographic device will introduce dead volume into the chromatographic device. However, since the present embodiment does not modify the portion of the chromatographic device other than the injection port of the injection assembly 20 to the front end of the chromatographic column 40, in this embodiment, "dead volume" refers to the volume between the "injection port of the injection assembly 20" and the front end of the chromatographic column 40.

[0063] Since the prior art performs chromatographic separation on the sample in the chromatographic column 40 in the injection mode, i.e., the mobile phase sequentially passes through the mobile phase outlet 504, the injection assembly 20, the filter unit 50, and the injection valve 10 before entering the chromatographic column 40 for chromatographic separation, the dead volume in the prior art can be calculated starting from the injection port of the injection assembly 20. However, in this embodiment, after the sample enters the injection valve 10, the injection valve 10 switches 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. i.e., the mobile phase directly enters the chromatographic column 40, rather than passing through the injection assembly 20, the filter unit 50, and the injection valve 10 before entering the chromatographic column 40. Therefore, the dead volume is calculated starting from the needle seat 30, which is equivalent to reducing the dead volume at the front end of the chromatographic column 40. The chromatographic separation process is no longer affected by the addition of the filter unit 50, and thus the analysis results are not affected.

[0064] 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.

[0065] In one embodiment, the filter unit 50 includes a housing 510 and a filter cartridge 520. The housing 510 is provided with a first channel 502, a second channel 503, and a filter cavity 501 for accommodating the filter cartridge 520. The first channel 502 connects the filter cavity 501 with the needle holder 30, while the second channel 503 connects the filter cavity 501 with the second interface 12. The first channel 502 has an outlet 504 communicating with the filter cavity 501, with a gap provided between the outlet 504 and the filter cartridge 520. This increases the effective filtration area of ​​the filter disc.

[0066] It is understandable that if there is no gap between the outlet and the filter element, that is, the outlet is pressed against 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 particulate matter in the sample will be blocked at the contact point between 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, it diffuses in the filter cavity, as shown in FIG. Figure 4As shown by the dashed line, the contact area between the sample and filter element 520 is increased. The effective filtration area of ​​filter element 520 is determined by its actual size. For example, if filter element 520 is circular and has a diameter of 2 mm, the effective filtration area is π mm². This means that the effective filtration area in this embodiment can be increased 100-fold, thereby extending the service life of filter element 520.

[0067] The number of injections and the system pressure were tested. If a conventional 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, making it unusable. However, when the filter unit 50 in this embodiment was used, 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 testing method is the conventional method, which will not be described in detail here.

[0068] Furthermore, the present application does not impose any restrictions on the shape or cross-sectional area of ​​the filter element, as long as the filter element can be matched with the filter cavity 501 or the bottom shell 511. It is also understood that the filter element is provided with a filter hole, and the present application does not impose any restrictions on 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 application requirements, and the present application does not limit the range of the gap.

[0069] In one embodiment, the outlet 504 is located above the filter element 520, and the height of the gap along the vertical direction is defined as H, with 100 μm ≤ H ≤ 1000 μm. If H is less than 100 μm, 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 1000 μm, 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 100 μm and 1000 μm. In this way, by increasing the distance between the outlet 504 and the filter element 520, the effective filtration area of ​​the filter disc is expanded.

[0070] 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.

[0071] 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 disc.

[0072] 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.

[0073] In one embodiment, the housing 510 includes a bottom shell 511 and a cover 512. The bottom shell 511 and the cover 512 are connected to enclose a filter chamber 501. A stopper 530 is further provided in the filter chamber 501. The stopper 530 abuts between the filter element 520 and the cover 512 to press the filter element 520 against the bottom shell 511. The stopper 530 maintains a stable distance between the filter element 520 and the cover 512, making the gap H more stable. This further ensures the filtering effect of the filter element 520 and further extends the service life of the filter element 520.

[0074] 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, the stopper 530 can be prevented from occupying too much surface area of ​​the filter element 520, thereby affecting the effective filtration area of ​​the filter element 520.

[0075] Furthermore, the cross section of the filter element 520 is circular, and the stopper 530 is provided 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.

[0076] In one embodiment, the filter element 520 is provided with filter holes with a pore size of 0.2 μm to 0.5 μm, so that the flow rate of the sample is not affected by the filter hole being too small, while the impurities in the sample can be effectively filtered out.

[0077] Furthermore, the filter element 520 is circular, and its diameter is between 2 mm and 3.2 mm. It is understood that if the diameter of the filter element 520 is less than 2 mm, the effective filtration area of ​​the filter element 520 is reduced. If the diameter of the filter element 520 is greater than 3.2 mm, the volume of the filter unit 50 is increased, making it more difficult for the sample to flow into the second channel 503, potentially causing sample loss and affecting the analysis results. Therefore, a diameter of the filter element 520 between 2 mm and 3.2 mm is more appropriate, as this increases the effective filtration area of ​​the filter element 520 without increasing the volume of the filter unit 50.

[0078] Illustratively, the diameter of the filter element 520 can 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.

[0079] In one embodiment, the cover 512 and the retaining member 530 are integrally formed. Thus, when replacing the filter element 520, the retaining member 530 is removed simultaneously with the cover 512, eliminating the need to remove and install the retaining member 530 separately. This saves the step of replacing the filter element 520 and avoids the risk of losing the retaining member 530 during the process.

[0080] In one embodiment, the injection assembly 20 includes an injection part 21, an injection pump 22, and a waste liquid collection part 23. 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 to temporarily store samples, and the injection needle 211 in the injection part 21 is used to selectively connect to the sample bottle 60 or the needle seat 30 to allow the sample to flow from the sample bottle 60 into the sample quantitative bottle or from the sample quantitative loop 212 into the needle seat 30. 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 loop 212 to flow sequentially through the injection needle 211, the needle seat 30, the injection valve 10, and into the chromatographic column 40. 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 within the chromatographic column 40. It will be appreciated that when the injection valve 10 is in the loading mode, after the sample enters the sample loop 212, due to the limited volume of the sample loop 212, excess sample will be discharged from the outlet 504 of the sample 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 loop 212.

[0081] 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, and the fourth interface 14 is connected to the fifth interface 15. 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, under the drive of 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.

[0082] 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, driven by 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.

[0083] 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.

[0084] In this way, automatic sample injection and chromatographic separation 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 and can also switch between injection mode and loading mode. In other embodiments, the injection valve 10 can also use a ten-way valve or other valves, and this application is not limited to this.

[0085] 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 magnetic bead method is used to pretreat the sample, 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 further avoiding causing the injection valve 10 to be blocked or worn.

[0086] Furthermore, the magnet can be set on the side of the sample bottle 60 or on the bottom of the sample bottle 60. This application does not limit this, as long as the magnet can absorb the magnetic material in the sample. Similarly, the number of magnets can be set according to the situation, and this application does not limit this.

[0087] 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:

[0088] S1: The injection valve 10 is placed in the sample loading mode, and the sample enters the injection assembly 20 and is temporarily stored in the injection assembly 20;

[0089] S2: Connect the injection assembly 20 and the needle seat 30;

[0090] 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;

[0091] S4: disconnect the injection assembly 20 from the needle seat 30, place the injection valve 10 in the sample loading mode, and perform chromatographic separation on the sample.

[0092] It will be appreciated that during the process of transferring the sample from the injection assembly 20 to the chromatographic column 40 and undergoing chromatographic separation within the chromatographic column 40, the injection assembly 20, needle seat 30, filter unit 50, and chromatographic column 40 can be separated by switching the injection valve 10 from the injection mode to the loading mode. This eliminates the effect of dead volume on chromatographic separation during the chromatographic separation of the sample within the chromatographic column 40. Furthermore, the injection assembly 20 can be detached from the needle seat 30 for cleaning or extraction of a new sample, preparing for the next injection and loading cycle.

[0093] 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, providing the filter unit between the second interface of the injection valve and the needle seat has no obvious adverse effect on the chromatographic fraction. For situations 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.

[0094] Furthermore, the filtration unit of the chromatographic device of the present application can effectively filter large impurities in the sample, preventing the sample from clogging or wearing out the injection valve and chromatographic column. Furthermore, it can extend the service life of the chromatographic device's piping, injection valve, and chromatographic column, thereby saving costs. In particular, when using the magnetic bead method to pretreat the sample, magnetic substances such as magnetic beads and impurities can be effectively removed.

[0095] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned 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.

[0096] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of patent protection for the present application shall be determined by the appended 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 a sampling mode for supplying a sample into the chromatographic column (40), and the injection valve (10) can switch between the loading mode and the sampling 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 the 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), and the sample can be transferred from the injection assembly (20) through the needle seat (30) and the injection valve (10) to the chromatographic column (40); It is characterized by: The chromatographic device further comprises a filtration unit (50), the filtration unit (50) being arranged on a flow path between the needle seat (30) and the second interface (12); the filtration unit (50) comprising a filter element (520), the filtration unit (50) being provided with a filtration cavity (501) for accommodating the filter element (520) and an outlet (504) communicating with the filtration cavity (501), the outlet (504) being communicated with the needle seat (30), and a gap being provided between the outlet (504) and the filter element (520); After the sample is transferred into the chromatographic column (40), the injection valve (10) is placed in a loading mode to perform chromatographic separation on the sample.

2. The chromatographic device according to claim 1, characterized in that The filter unit (50) further comprises a housing (510), wherein the housing (510) is provided with a first channel (502), a second channel (503) and the filter cavity (501). 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 outlet (504) is provided in the first channel (502).

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 enclose the filter cavity (501); a limiting member (530) is further provided in the filter cavity (501); the limiting member (530) is held between the filter element (520) and the cover body (512) 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 annular, 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 provided at the edge of the filter element (520); And / or, the filter element (520) is provided with a filter hole, and the pore size of the filter hole is 0.2 micrometer to 0.5 micrometer; 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 member (530) are integrally formed.

8. The chromatographic device according to claim 1, characterized in that The injection assembly (20) includes an injection part (21), an injection pump (22) and a waste liquid collection part (23), the injection valve (10) also includes a third interface (13), a fourth interface (14), a fifth interface (15) and a sixth interface (16), and the chromatographic device also includes 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 connected to the sample injection part (21), and the sample injection part (21) is used to temporarily store samples. The sixth interface (16) is in communication with the solvent pump (70), When the injection valve (10) is in the 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), and 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. 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 includes 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 and 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, 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 sample loading mode, and the sample is subjected to chromatographic separation.

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