Two-dimensional liquid phase system

Abstract

The utility model relates to a two-dimensional liquid phase system which comprises a hydrophilic interaction chromatographic column, a reversed-phase chromatographic column, a detector, an automatic sample injector, a first pump assembly, a second pump assembly, a sample temporary storage unit and a switching valve, the first pump assembly is communicated with the hydrophilic interaction chromatographic column and is used for pushing a sample loading solution and carrying out gradient elution on the hydrophilic interaction chromatographic column; the second pump assembly is communicated with the reversed-phase chromatographic column and is used for carrying out gradient elution on the reversed-phase chromatographic column; wherein the switching valve comprises a first double-four-way valve and a second double-four-way valve which are communicated with each other; the switching valve has at least two connection states through position switching: state 1: the switching valve communicates a liquid inlet of the detector with a liquid outlet of the hydrophilic interaction chromatographic column; and state 2: the switching valve communicates the liquid inlet of the detector with the liquid outlet of the reversed-phase chromatographic column, and communicates the first port of the sample temporary storage unit with the liquid inlet of the hydrophilic interaction chromatographic column. The system can realize one-time analysis of a multi-component target object with relatively large polarity difference.

Description

Technical Field

[0001] This utility model relates to the field of instrumental analysis technology, and in particular to a two-dimensional liquid phase system. Background Technology

[0002] In cutting-edge fields such as metabolomics exploration, environmental monitoring, and agricultural and veterinary drug residue analysis, the accurate analysis of multiple target compounds is a routine requirement. However, when these target compounds have a wide and significantly different polarity range, a single analytical strategy is often insufficient for comprehensive analysis, especially when dealing with complex samples containing both highly polar and weakly polar substances. Traditional approaches have relied on two distinct analytical pathways and column configurations—using hydrophilic columns for the analysis of highly polar components and reversed-phase columns for the analysis of weakly polar components. However, this separate approach not only significantly increases the time and labor intensity of the analysis but also generates twice the amount of data due to repetitive operations, hindering the improvement of overall analytical efficiency. Utility Model Content

[0003] Based on this, the purpose of this utility model is to provide a two-dimensional liquid phase system, which uses two double four-way valves as the connection hub to connect hydrophilic interaction chromatography and reversed-phase chromatography, so as to realize the one-time analysis of multi-component target substances with large polarity differences.

[0004] A two-dimensional liquid chromatography system includes a first pump assembly, a hydrophilic interaction chromatographic column connected to the outlet of the first pump assembly, a switching valve connected to the outlet of the hydrophilic interaction chromatographic column, and a detector connected to the hydrophilic interaction chromatographic column through the switching valve; a sample injector is provided in the connecting pipeline between the first pump assembly and the hydrophilic interaction chromatographic column, and the first pump assembly is used to push the sample loading solution and perform gradient elution on the hydrophilic interaction chromatographic column;

[0005] The switching valve is also connected to a second pump assembly, a sample storage unit and a reversed-phase chromatography column. The outlet of the second pump assembly is connected to the inlet of the reversed-phase chromatography column through the switching valve. The outlet of the reversed-phase chromatography column is connected to the switching valve. The second pump assembly is used for gradient elution of the reversed-phase chromatography column.

[0006] The switching valve can switch between at least two of the following connection states depending on its position:

[0007] Connection state 1: The switching valve connects the inlet of the detector to the outlet of the hydrophilic interaction chromatographic column;

[0008] Connection state 2: The switching valve connects the inlet of the detector to the outlet of the reversed-phase chromatography column, and connects the first port of the sample storage unit to the inlet of the reversed-phase chromatography column;

[0009] The switching valve consists of a first double four-way valve and a second double four-way valve that are interconnected.

[0010] By switching between the first and second double four-way valves with identical structures, hydrophilic interaction chromatography mode (first dimension) and reversed-phase chromatography mode (second dimension) can be realized successively. When the first and second double four-way valves are switched to connection state 1, the system flow path can complete the process of loading hydrophilic interaction chromatographic column or separating and detecting strongly polar substances. When the switching valve is switched to connection state 2, the system flow path can complete the process of collecting weakly polar substances or separating and detecting weakly polar substances.

[0011] The two-dimensional liquid chromatography system of this invention uses two dual four-way valves as the connecting hub to connect a hydrophilic interaction chromatographic column and a reversed-phase chromatographic column. The hydrophilic interaction chromatographic column has the characteristic of retaining and separating strongly polar substances, while the reversed-phase chromatographic column has the characteristic of retaining and separating weakly polar substances. This system, obtained using simple hardware and a simple flow path design, achieves the separation of weakly polar to strongly polar substances with a single injection and can be coupled with ultraviolet detectors or mass spectrometry for analysis.

[0012] Furthermore, the sample storage unit has a first port and a second port; the outlet of the hydrophilic chromatographic column, the first port and the second port of the sample storage unit, and the outlet of the reversed-phase chromatographic column are respectively connected to the first dual four-way valve; the inlet of the reversed-phase chromatographic column, the inlet of the detector, and the outlet of the second pump assembly are respectively connected to the second dual four-way valve.

[0013] Furthermore, the sample storage unit is a trapping column with a first port and a second port; the switching valve also has the following connection states by switching its position: Connection state 0: The switching valve connects the first port of the sample storage unit to the outlet of the hydrophilic interaction chromatography column, and connects the outlet of the second pump assembly to the pipeline between the outlet of the hydrophilic interaction chromatography column and the first port of the sample storage unit, so as to dilute the solution flowing out of the hydrophilic interaction chromatography column.

[0014] Further, in connection state 0, the switching valve connects the first port of the sample storage unit to the outlet of the second pump assembly, and connects the second port of the sample storage unit to the detector or to an external system; in connection state 2, the switching valve connects the second port of the sample storage unit to the outlet of the second pump assembly, and connects the first port of the sample storage unit to the inlet of the reversed-phase chromatography column.

[0015] Furthermore, the second pump assembly includes a third chromatographic pump and a fourth chromatographic pump, and a second mixer connected to the outlet of the third chromatographic pump and the outlet of the fourth chromatographic pump, respectively; the outlet of the second mixer is connected to the second dual four-way valve.

[0016] Furthermore, the second mixer is a three-way mixer, with two ports being inlets that are connected to the outlets of the third and fourth chromatographic pumps via pipelines, respectively; the other port is an outlet that is connected to the second double four-way valve via a pipeline.

[0017] Furthermore, the first pump assembly includes a first chromatographic pump and a second chromatographic pump, and a first mixer connected to the first chromatographic pump and the second chromatographic pump respectively; the outlet of the first chromatographic pump and the outlet of the second chromatographic pump are connected to the inlet of the hydrophilic interaction chromatographic column through the first mixer; the injector is disposed on the pipeline connecting the first mixer and the hydrophilic interaction chromatographic column.

[0018] Furthermore, the first mixer is a three-way mixer, wherein two ports are liquid inlets, which are respectively connected to the liquid outlet of the first chromatographic pump and the liquid outlet of the second chromatographic pump through pipelines; the other port is a liquid outlet, which is connected to the liquid inlet of the hydrophilic interaction chromatographic column through pipelines.

[0019] Furthermore, the first pump assembly includes a first chromatographic pump, a low-pressure gradient proportioning valve built into the first chromatographic pump, and a first mixer connected to the first chromatographic pump; the outlet of the first chromatographic pump is connected to the inlet of the hydrophilic interaction chromatographic column through the first mixer; the injector is disposed on the pipeline connecting the first mixer and the hydrophilic interaction chromatographic column.

[0020] Furthermore, the two-dimensional liquid phase system also includes a third mixer, and the outlet of the second pump assembly is connected to the outlet of the hydrophilic interaction chromatographic column and the first dual four-way valve through the third mixer.

[0021] It should be noted that the first pump assembly has the capability to deliver at least two solvents with opposite polarities, enabling gradient elution in the first-dimensional liquid phase. In the aforementioned two-dimensional liquid phase system, in the first dimension, the first pump assembly can freely choose a combination of "one pump + gradient proportioning valve" or "two pumps." Both configurations can achieve mixing before injection to realize gradient separation in the first dimension. In the second dimension, a binary high-pressure gradient system is formed by a third and a fourth chromatographic pump. Through the aforementioned specific flow path design, mixing before injection is achieved to solve the solvent effect problem in the second dimension. Specifically, in the second-dimensional liquid phase, the "switching valve + sample storage unit" constitutes an equivalent injection system. When the sample storage unit is a trapping column, since the trapping column is a reversed-phase material, and the solvent delivered by the first pump assembly 301 is a high-proportion organic phase (ACN, acetonitrile) mixed solvent, ACN is a strong solvent for the trapping column. If a high proportion of ACN carries weakly polar substances into the sample storage unit, a strong solvent effect will easily occur, making it impossible for the trapping column to retain the weakly polar substances. To address this issue, this invention also implements a dilution mode by switching between a first dual four-way valve and a second dual four-way valve. When the system enters connection state 0, the solvent containing weakly polar substances flowing out of the hydrophilic interaction column is diluted online by high-flow-rate water. Specifically, the first pump assembly first delivers a low-flow-rate ACN to carry out the solution from the hydrophilic interaction column. Then, the solution is mixed with a high-flow-rate, high-proportion aqueous mixed solution delivered by the second pump assembly in the third mixer. This dilutes the ACN in the solution with high-flow-rate water, transforming it into an aqueous mixed solvent containing a low proportion of ACN. When the solution enters the sample storage unit, no solvent effect occurs, and the weakly polar substances can be retained on the collection column.

[0022] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the first embodiment of the two-dimensional liquid phase system of this utility model (connection state 0);

[0024] Figure 2 This is a schematic diagram of the structure of the first embodiment of the two-dimensional liquid phase system of this utility model (connection state 1).

[0025] Figure 3 This is a schematic diagram of the structure of the first embodiment of the two-dimensional liquid phase system of this utility model (connection state 2);

[0026] Figure label:

[0027] 101. First double four-way valve; 102. Second double four-way valve;

[0028] 201. Hydrophilic interaction column; 202. Reversed-phase column;

[0029] 301, First pump assembly; 3010, First chromatography pump; 3012, Second chromatography pump; 3014, First mixer;

[0030] 302, Second pump assembly; 3020, Third chromatography pump; 3022, Fourth chromatography pump; 3024, Second mixer;

[0031] 40. Third mixer;

[0032] 50. Sample temporary storage unit;

[0033] 60. Sample injector;

[0034] 70. Detector. Detailed Implementation

[0035] It should be understood that the described embodiments are merely some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of the embodiments of this application.

[0036] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0037] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is described as "connected" or "fixedly connected" to another component, it can be directly connected to the other component or there may be an intervening component.

[0038] To enable the one-time analysis of multi-component target analytes with significant polarity differences, this invention provides a two-dimensional liquid chromatography system, including a first pump assembly, a hydrophilic interaction chromatographic column connected to the outlet of the first pump assembly, a switching valve connected to the outlet of the hydrophilic interaction chromatographic column, and a detector connected to the hydrophilic interaction chromatographic column via the switching valve; the connecting pipeline between the first pump assembly and the hydrophilic interaction chromatographic column is equipped with an injector for sample loading, and the first pump assembly is used to push the sample loading solution and perform gradient elution on the hydrophilic interaction chromatographic column;

[0039] The switching valve is also connected to a second pump assembly, a sample storage unit and a reversed-phase chromatography column. The outlet of the second pump assembly is connected to the inlet of the reversed-phase chromatography column through the switching valve. The outlet of the reversed-phase chromatography column is connected to the switching valve. The second pump assembly is used for gradient elution of the reversed-phase chromatography column.

[0040] The switching valve consists of a first double four-way valve and a second double four-way valve that are interconnected.

[0041] The switching valve can switch between at least two of the following connection states depending on its position:

[0042] Connection Status 1: The switching valve connects the detector inlet to the outlet of the hydrophilic column;

[0043] Connection Status 2: The switching valve connects the detector inlet to the reversed-phase column outlet and connects the first port of the sample storage unit to the reversed-phase column inlet.

[0044] Furthermore, when the sample storage unit is collecting the column, in order to temporarily retain weakly polar substances in the sample on the collection column, the above-mentioned two-dimensional liquid phase system can also achieve the following connection states by switching the position of the switching valve:

[0045] Connection Status 0: The switching valve connects the first port of the sample storage unit to the outlet of the hydrophilic interaction chromatography column, and connects the outlet of the second pump assembly to the pipeline between the outlet of the hydrophilic interaction chromatography column and the first port of the sample storage unit, so as to dilute the solution flowing out of the hydrophilic interaction chromatography column.

[0046] The present invention will now be described in detail with reference to the accompanying drawings.

[0047] Figure 1-3 The specific structure of one embodiment of the two-dimensional liquid phase system of this utility model is shown. For example... Figure 1-3 As shown, in this embodiment, the switching valve is formed by interconnecting a first double four-way valve 101 and a second double four-way valve 102, both of which have a pressure resistance of over 50 MPa.

[0048] Specifically, the first double four-way valve 101 has an eight-way structure with eight ports, which are arranged in a counterclockwise order from the inside to the outside as a, b, c, d, e, f, g and h; the second double four-way valve 102 has an eight-way structure with eight ports arranged in a counterclockwise order as a', b', c', d', e', f', g' and h'.

[0049] The first pump assembly 301 includes a first chromatographic pump 3010 for providing an organic phase and a second chromatographic pump 3012 for providing an aqueous solution. To mix the organic phase (ACN) with the aqueous solution, the outlets of the first chromatographic pump 3010 and the second chromatographic pump 3012 are connected to a first mixer 3014. The first mixer 3014 is a three-way mixer with a pressure resistance of 50 MPa or higher. The first mixer 3014 has three ports: m, n, and o, where ports m and n are inlets, and port o is an outlet. The second pump assembly 302 includes a third chromatographic pump 3020 for conveying a low-flow-rate ACN and a fourth chromatographic pump 3022 for conveying a high-flow-rate water. To mix the organic phase and the aqueous solution, the outlets of the third chromatographic pump 3020 and the fourth chromatographic pump 3022 are connected to a second mixer 3024. The second mixer 3024 is also a three-way mixer with a pressure resistance of over 50MPa. It has three interfaces: m', n', and o'. Interfaces m' and n' are liquid inlets, and interface o' is a liquid outlet.

[0050] The ports of the first double four-way valve 101 and the second double four-way valve 102, as well as the three ends of the first mixer 3014, are standard threaded joints suitable for connecting standard polyether ether ketone connectors or stainless steel connectors.

[0051] The connection configuration of the two-dimensional liquid phase system in this embodiment is as follows:

[0052] The outlet of the first chromatographic pump 3010 and the outlet of the second chromatographic pump 3012 are respectively connected to interface m and interface n of the first mixer 3014. Interface o of the first mixer 3014 is connected to the inlet of the hydrophilic interaction chromatographic column 201 through a pipeline. The outlet of the hydrophilic interaction chromatographic column 201 is connected to interface a of the first double four-way valve 101 through the third mixer 40. Specifically, the third mixer 40 is also a three-way mixer with a pressure resistance of more than 50 MPa, and it has three interfaces: m”, n”, and o”. Interfaces m” and n” are inlets, and interface o” is an outlet. The outlet of the hydrophilic interaction chromatographic column 201 is connected to interface m” of the third mixer 40 through a pipeline. Interface o” of the third mixer 40 is connected to interface a of the first double four-way valve 101 through a pipeline. An injector 60 is provided on the connecting pipeline between the first mixer 3014 and the hydrophilic interaction chromatographic column 201 to inject the sample into the pipeline.

[0053] The outlet of the third chromatographic pump 3020 and the outlet of the fourth chromatographic pump 3022 are respectively connected to the interface m' and interface n' of the second mixer 3024. The interface o' of the second mixer 3024 is connected to the interface f' of the second double four-way valve 102 through a pipeline, and is connected to the interface n of the third mixer 40 through the second double four-way valve 102.

[0054] The inlet of the mass spectrometer detector 70 is connected to the interface c' of the second double four-way valve 102. The first port of the sample storage unit 50 is connected to the interface b of the first double four-way valve 101, and its second port is connected to the interface e of the first double four-way valve 101. The interface f of the first double four-way valve 101 is connected to the interface e' of the second double four-way valve 102. The interface a' of the second double four-way valve 102 serves as a waste liquid outlet connected to the outside of the system, specifically connected to a waste liquid bottle. The sample storage unit 50 is specifically a collection column.

[0055] The first double four-way valve 101 and the second double four-way valve 102, through their position switching cooperation, can achieve the following three connection states:

[0056] Connection state 0: such as Figure 1 As shown, the first dual four-way valve 101 has its port a connected to port b via a pipe, port e connected to port h, and port d connected to port c via a pipe; the second dual four-way valve 102 has its port b' connected to port a' via a pipe, port e' connected to port h', and port f' connected to port g'. Through the internal flow paths of the first dual four-way valve 101 and the second dual four-way valve 102, the port o' of the second mixer 3024 is connected to the port n" of the third mixer 40. The port o" of the third mixer 40 is connected to the first port of the sample storage unit 50, and its second port is connected to the detector 70 or an external system.

[0057] Connection state 1: such as Figure 2 As shown, the first dual four-way valve 101 has its ports a, d, g, and h connected sequentially via tubing, with port f connected to port e and port b connected to port c. The second dual four-way valve 102 has its port h' connected to port e' and port b' connected to port a'. Through the internal flow paths of the first and second dual four-way valves 101 and 102, the inlet of the detector 70 is connected to the outlet of the hydrophilic column 201. Here, although the sample storage unit 50 is connected to the reversed-phase column 202 via tubing, in connection state 1, no solution flows through the sample storage unit 50, the reversed-phase column 202, or their connecting tubing.

[0058] Connection state 2: such as Figure 3As shown, the first dual four-way valve 101 has its ports a, d, g, and h connected sequentially via pipelines, port f connected to port e, and port b connected to port a. The second dual four-way valve 102 has its port f' connected to port e' via pipelines, port b' connected to port c', port g' connected to port h', and port d' connected to port a' via pipelines. Port a' serves as a waste outlet connected to the outside of the system. Through the internal flow paths of the first and second dual four-way valves 101 and 102, the inlet of the detector 70 is connected to the outlet of the reversed-phase chromatography column 202, the first port of the sample storage unit 50 is connected to the inlet of the reversed-phase chromatography column 202, and the outlet of the hydrophilic interaction chromatography column 201 is connected to the waste outlet a'.

[0059] The analysis process based on the above two-dimensional liquid phase system is as follows:

[0060] (1) Sample loading onto hydrophilic column 201, collection of weakly polar substances:

[0061] like Figure 1 As shown, the first dual four-way valve 101 and the second dual four-way valve 102 are switched to connection state 0. Then, the injector 60 introduces the sample containing both highly polar and weakly polar substances into the system. The first chromatographic pump 3010 and the second chromatographic pump 3012 respectively output organic and aqueous phase solvents to the first mixer 3014 to mix and form a high-proportion organic phase mixed solvent, which then pushes the sample into the hydrophilic interaction chromatographic column 201. The highly polar substances of the sample are retained at the head of the hydrophilic interaction chromatographic column 201, while the weakly polar substances are... Polar substances are eluted and elute; at this time, the third chromatographic pump 3020 and the fourth chromatographic pump 3022 respectively deliver organic phase solvent and aqueous phase solvent to the second mixer 3024 for mixing to form a high proportion of aqueous phase mixed solvent. The high proportion of aqueous phase mixed solvent then enters the third mixer 40, where the high proportion of organic phase mixed solvent flowing out of the hydrophilic column 201 is diluted so that the weakly polar substances that subsequently flow to the sample storage unit 50 can be retained on the sample storage unit 50.

[0062] In the above process, the first pump assembly 301 initially delivers a high proportion of weak solvent (of which the volume ratio of organic solvent is >95%) to the hydrophilic interaction column 201, and both strongly polar substances and weakly polar substances are retained in the hydrophilic interaction column 201; as the proportion of aqueous solvent in the solvent delivered by the first pump assembly 301 increases, the elution ability becomes stronger, and weakly polar substances are eluted first from the hydrophilic interaction column 201;

[0063] After the organic and aqueous phase solvents delivered by the third and fourth chromatographic pumps 3020 and 3022 are mixed in the second mixer 3024, the volume ratio of the aqueous phase solvent in the mixed solvent should be maintained >90% to ensure a high proportion of weak solvent environment in the reversed-phase chromatographic column 202.

[0064] (2) Strongly polar substances separate, and weakly polar substances focus:

[0065] like Figure 2 As shown, the first dual four-way valve 101 and the second dual four-way valve 102 are switched to connection state 1. The proportion of aqueous solvent in the solvent delivered by the first pump assembly 301 continues to increase, and the highly polar substances retained on the hydrophilic chromatographic column 201 are eluted by gradient. The highly polar substances enter the mass spectrometer detector 70 through the first dual four-way valve 101 for detection, and a chromatogram of the highly polar substances is obtained.

[0066] The volume ratio of aqueous solvent in the delivery solvent of the first pump assembly 301 gradually increases to 50% to 60%, the elution ability becomes stronger, and the strongly polar substances retained on the hydrophilic interaction chromatographic column 201 are eluted sequentially. Then this ratio is maintained to ensure that the strongly retained impurities in the hydrophilic interaction chromatographic column 201 are eluted so as not to interfere with the analysis of the next sample.

[0067] The flow rate of the high-proportion aqueous mixed solvent delivered by the second pump assembly 302 is much greater than that of the high-proportion organic solvent delivered by the first pump assembly 301 (e.g., volume flow rate ratio > 9:1), so as to ensure that the weakly polar substance to be tested retained in the sample storage unit 50 in process (1) dissolves in the high-proportion aqueous mixed solvent delivered by the second pump assembly 302, forming a high-proportion aqueous mixed solvent (where the volume ratio of the aqueous solvent is > 90%) carrying the weakly polar substance to be tested, and then pushes it into the reversed-phase chromatography column 202 to ensure a high-proportion weak solvent environment so that the weakly polar substance to be tested is focused at the column head of the reversed-phase chromatography column 202;

[0068] In addition, the high proportion of aqueous mixed solvent delivered by the second pump assembly 302 flows into the sample storage unit 50, pushing the weakly polar substance to be tested into the reversed-phase chromatography column 202 in the opposite direction to the direction in which the solvent delivered by the first pump assembly 301 in process (1) elutes the weakly polar substance to be tested in the hydrophilic chromatography column 201 into the sample storage unit 50. This is beneficial for the weakly polar substance to be tested to quickly enter the reversed-phase chromatography column 202 for focusing.

[0069] (3) Equilibrium of column 201 for hydrophilic interaction, separation of weakly polar substances:

[0070] After the separation and detection of highly polar substances on the hydrophilic column 201 are completed, the first dual four-way valve 101 and the second dual four-way valve 102 switch to... Figure 3In connection state 2, the first pump assembly 301 delivers a high proportion of organic phase solvent into the hydrophilic interaction chromatographic column 201, and the solvent exiting the hydrophilic interaction chromatographic column 201 is discharged from the system; at the same time, the third chromatographic pump 3020 and the fourth chromatographic pump 3022 deliver organic phase solvent and aqueous phase solvent respectively into the second mixer 3024 for mixing, and the resulting high proportion of aqueous phase mixed solvent enters the reversed-phase chromatographic column 202. Over time, the proportion of organic phase solvent in the mixed solvent increases, and the weakly polar substances focused on the head of the reversed-phase chromatographic column 202 are eluted one by one. The weakly polar substances pass through the first double four-way valve 101 and the second double four-way valve 102 in sequence, and finally enter the mass spectrometer detector 70 for detection, to obtain the chromatogram of the weakly polar substances.

[0071] In this process, the first pump assembly 301 delivers a high proportion of weak solvent (of which the volume ratio of organic phase solvent is >95%) to balance the hydrophilic interaction of the chromatographic column 201, preparing it for the analysis of the next sample.

[0072] The total flow rate of the third chromatographic pump 3020 and the fourth chromatographic pump 3022 remains constant. The flow rate of the organic phase solvent delivered by the third chromatographic pump 3020 gradually increases, and the elution capacity becomes stronger. The weakly polar components focused on the head of the reversed-phase column 202 in process (2) are eluted sequentially. Then, the organic phase solvent is maintained at a high proportion (volume proportion > 95%) to ensure that the strong retention impurities in the reversed-phase column 202 are eluted so as not to interfere with the analysis of the next sample.

[0073] (4) Return to the initial state:

[0074] All substances retained on the reversed-phase column 202 were eluted to the mass spectrometer detector 70, and the reversed-phase column 202 was thoroughly cleaned with a strong solvent. The system was then restored to the state of process (1) and awaited the next sample injection.

[0075] The two-dimensional liquid phase system of this invention has the following beneficial technical effects:

[0076] (1) Weakly polar and strongly polar substances can be analyzed at the same time. The same sample does not need to be analyzed by different methods for weakly polar and strongly polar substances. Only one detector is needed. The spectra obtained by hydrophilic interaction chromatography and reversed phase chromatography are saved in one data file, saving time and reducing redundant data.

[0077] (2) In addition to being used to analyze weakly polar and strongly polar substances, this system can also be used to separate these two types of substances, playing the role of online pretreatment, that is, removing the interference of polar matrix to analyze the weakly polar substances, or removing the interference of non-polar matrix to analyze the strongly polar substances.

[0078] (3) The two analytical methods of hydrophilic interaction chromatography and reversed-phase chromatography are connected online and automatically switched without manual operation, which improves work efficiency. The hydrophilic interaction chromatography column separates while the reversed-phase chromatography column is balanced, and vice versa, which saves the time of column balancing on a macroscopic scale.

[0079] (4) Different hydrophilic chromatography columns and reversed-phase chromatography columns can be selected according to the specific analysis items, which has strong scalability.

[0080] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and this utility model also intends to include these modifications and variations.

Claims

1. A two-dimensional liquid phase system, characterized in that: The system includes a first pump assembly (301), a hydrophilic interaction chromatographic column (201) connected to the outlet of the first pump assembly (301), a switching valve connected to the outlet of the hydrophilic interaction chromatographic column (201), and a detector (70) connected to the hydrophilic interaction chromatographic column (201) through the switching valve; the connecting pipeline between the first pump assembly (301) and the hydrophilic interaction chromatographic column (201) is provided with an injector (60) for sample loading, and the first pump assembly (301) is used to push the sample loading solution and perform gradient elution on the hydrophilic interaction chromatographic column (201); The switching valve is also connected to a second pump assembly (302), a sample storage unit (50), and a reversed-phase chromatography column (202). The outlet of the second pump assembly (302) is connected to the inlet of the reversed-phase chromatography column (202) through the switching valve. The outlet of the reversed-phase chromatography column (202) is connected to the switching valve. The second pump assembly (302) is used for gradient elution of the reversed-phase chromatography column (202). The switching valve can switch between at least two of the following connection states depending on its position: Connection state 1: The switching valve connects the inlet of the detector (70) to the outlet of the hydrophilic interaction chromatographic column (201); Connection state 2: The switching valve connects the inlet of the detector (70) to the outlet of the reversed-phase chromatography column (202) and connects the first port of the sample storage unit (50) to the inlet of the reversed-phase chromatography column (202); The switching valve consists of a first double four-way valve (101) and a second double four-way valve (102) that are interconnected.

2. The two-dimensional liquid phase system according to claim 1, characterized in that: The sample storage unit (50) has a first port and a second port; The outlet of the hydrophilic chromatographic column (201), the first port and the second port of the sample storage unit (50), and the outlet of the reversed-phase chromatographic column (202) are respectively connected to the first double four-way valve (101). The inlet of the reversed-phase chromatographic column (202), the inlet of the detector (70), and the outlet of the second pump assembly (302) are respectively connected to the second double four-way valve (102).

3. The two-dimensional liquid phase system according to claim 1, characterized in that: The sample storage unit (50) is a collection column, which has a first port and a second port; The switching valve, depending on its position switching, also has the following connection states: Connection State 0: The switching valve connects the first port of the sample storage unit (50) to the outlet of the hydrophilic interaction chromatographic column (201), and connects the outlet of the second pump assembly (302) to the pipeline between the outlet of the hydrophilic interaction chromatographic column (201) and the first port of the sample storage unit (50), so as to dilute the solution flowing out of the hydrophilic interaction chromatographic column (201).

4. The two-dimensional liquid phase system according to claim 3, characterized in that: In the connection state 0, the switching valve connects the first port of the sample storage unit (50) to the outlet of the second pump assembly (302), and connects the second port of the sample storage unit (50) to the detector (70) or to an external system. In the connection state 2, the switching valve connects the second port of the sample storage unit (50) to the outlet of the second pump assembly (302) and connects the first port of the sample storage unit (50) to the inlet of the reversed phase chromatography column (202).

5. The two-dimensional liquid phase system according to claim 1, characterized in that: The second pump assembly (302) includes a third chromatographic pump (3020) and a fourth chromatographic pump (3022), and a second mixer (3024) connected to the outlet of the third chromatographic pump (3020) and the outlet of the fourth chromatographic pump (3022), respectively; the outlet of the second mixer (3024) is connected to the second double four-way valve (102).

6. The two-dimensional liquid phase system according to claim 5, characterized in that: The second mixer (3024) is a three-way mixer, with two ports being inlets that are connected to the outlets of the third and fourth chromatographic pumps via pipelines, respectively; and the other port being an outlet that is connected to the second double four-way valve (102) via pipelines.

7. The two-dimensional liquid phase system according to claim 1, characterized in that: The first pump assembly (301) includes a first chromatographic pump (3010) and a second chromatographic pump (3012), and a first mixer (3014) respectively connected to the first chromatographic pump (3010) and the second chromatographic pump (3012); The outlet of the first chromatographic pump (3010) and the outlet of the second chromatographic pump (3012) are connected to the inlet of the hydrophilic chromatographic column (201) through the first mixer (3014); The injector (60) is disposed on the pipeline connecting the first mixer (3014) and the hydrophilic chromatographic column (201).

8. The two-dimensional liquid phase system according to claim 7, characterized in that: The first mixer (3014) is a three-way mixer, with two ports being inlets that are connected to the outlets of the first chromatographic pump (3010) and the second chromatographic pump (3012) via pipelines, respectively; the other port is an outlet that is connected to the inlet of the hydrophilic interaction chromatographic column (201) via pipelines.

9. The two-dimensional liquid phase system according to claim 1, characterized in that: The first pump assembly (301) includes a first chromatographic pump (3010), a low-pressure gradient proportioning valve built into the first chromatographic pump (3010), and a first mixer (3014) in communication with the first chromatographic pump (3010); The outlet of the first chromatographic pump (3010) is connected to the inlet of the hydrophilic chromatographic column (201) through the first mixer (3014); The injector (60) is disposed on the pipeline connecting the first mixer (3014) and the hydrophilic chromatographic column (201).

10. The two-dimensional liquid phase system according to claim 1, characterized in that: It also includes a third mixer (40), the outlet of the second pump assembly (302) being connected to the outlet of the hydrophilic interaction chromatographic column (201) and the first double four-way valve (101) through the third mixer (40).

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