Inhibition system for ion chromatography

Abstract

The invention discloses a suppression system for ion chromatography. The suppression system comprises a sample injection valve, a chromatographic column, a suppressor and a conductivity detector which are sequentially communicated through a pipeline, the sample injection valve can be respectively communicated with a sample liquid and a flow channel so as to complete sample injection; the chromatographic column is used for mutually separating ion components in a sample solution; the suppressor is used for reducing the background conductivity in the mobile phase; and the conductivity detector is used for measuring the conductivity of the mobile phase flowing through the suppressor and the conductivity of the sample liquid so as to calculate the concentration of each ion in the sample liquid. The suppressor comprises a shell and a valve head stator, a plurality of suppression channels which are arranged in the circumferential direction are formed in the shell, the suppression channels are used for being filled with suppression exchange resin, and the suppression channels are in a U shape. The device is reasonable in structure, good in pressure resistance and high in continuous working efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of ion chromatography, and particularly to an inhibition system for ion chromatography. Background Art

[0002] Ion chromatography is a high-performance liquid chromatography technology for separating and quantitatively analyzing ionic compounds. It is widely used in fields such as environmental monitoring, water quality analysis, food inspection, and pharmaceutical industry. In the ion chromatography detection operation, the suppressor column is one of the key components, which is used to improve the detection sensitivity and selectivity. It enhances the intensity of the target ion signal by removing the background conductivity. Among them, the resin-packed suppressor column is widely used due to its low cost and mature technology. In practice, after one operation, the suppressor column needs to be regenerated and rinsed with ultrapure water for balance before the next operation, which is not conducive to continuous analysis and improving the detection efficiency.

[0003] In addition, the existing resin-packed suppressor columns often adopt a through-flow structure, which cannot achieve continuous operation. Moreover, the through-flow suppressor columns need to be connected with external pipelines, resulting in a large dead volume. The large dead volume will cause the baseline to be unstable or drift, and even affect the accuracy of the chromatographic analysis results. In addition, due to the use requirements, the external pipelines are often relatively narrow and difficult to have high-pressure resistance. In addition, the structures of the suppressor columns that can operate continuously in the existing technology often have poor high-pressure resistance. When the input mobile phase has a large pressure and high concentration and cannot be effectively buffered, the high-pressure fluid will not only cause slight compression of the exchange resin. Especially for large-particle or soft resins, this compression effect will change the effective porosity of the resin bed, thereby affecting the fluid distribution uniformity and contact time, resulting in poor separation effect. In addition, in an extremely high-pressure environment, it will also affect the activity of the functional groups in the exchange resin, which is not conducive to improving the separation effect. Moreover, the high-pressure fluid is also prone to cause seal failure and even damage the suppressor column, which is not conducive to the stable and continuous progress of the detection and inspection activities. Summary of the Invention

[0004] The present invention discloses an inhibition system for ion chromatography, which solves the technical problems in the prior art that the suppressor column needs to work intermittently with low efficiency and limited pressure resistance, and has the technical effects of reasonable structure, good pressure resistance and high continuous working efficiency. The technical solutions adopted are as follows: An inhibition system for ion chromatography includes an injection valve, a chromatographic column, a suppressor, and a conductivity detector that are sequentially connected in series through pipelines; The injection valve can be respectively communicated with the sample solution and the mobile phase to complete sample injection; The chromatographic column is used to separate the ionic components in the sample solution from each other; The suppressor is used to reduce the background conductivity of the mobile phase. The suppressor includes a housing and a valve head stator. A valve core is rotatably connected inside the housing. A plurality of suppression passages arranged circumferentially are formed inside the valve core. The suppression passages are used to fill the exchange resin for suppression. The suppression passages are U-shaped and form an inlet and an outlet on the end face of the valve core. The valve head stator is fixedly arranged on the housing and is provided with a plurality of flow-through passages that can be respectively communicated with the inlets and outlets of the suppression passages. When the valve core rotates relative to the valve head stator under the action of an external driving unit, a plurality of suppression passages can work in sequence.

[0005] The conductivity detector measures the conductivity of the mobile phase and the sample solution flowing through the suppressor to calculate the concentration of each ion in the sample solution.

[0006] Based on the above technical solution, the valve core includes a valve body. A core body is sleeved inside the valve body, and a top end cover and a bottom end cover are respectively arranged at both ends of the core body. The core body, the top end cover and the bottom end cover jointly form a plurality of suppression passages; the suppression passages form stepped holes on the top end cover, through holes on the core body, and long grooves on the bottom end cover.

[0007] Based on the above technical solution, the core body is in interference fit with the valve body, the top end cover and the bottom end cover are in clearance fit with the valve body. The top end cover and the core body are positioned by a plurality of axially arranged first positioning columns, and the bottom end cover and the core body are positioned by a plurality of axially arranged second positioning columns. The top end cover, the core body and the bottom end cover are axially pressed on the valve head stator.

[0008] Based on the above technical solution, first bosses surrounding the suppression passages are included on the end faces of the top end cover, the core body and the bottom end cover facing each other and on the end face of the top end cover facing the valve head stator. The valve head stator, the top end cover, the core body and the bottom end cover are abutted against each other through the first bosses to seal the suppression passages.

[0009] Based on the above technical solution, second bosses surrounding the flow-through passages are provided on the end face of the valve head stator facing the top end cover. The valve head stator and the top end cover are abutted against each other through the second bosses to seal the flow-through passages.

[0010] On the basis of the above technical solution, it further includes a liquid passing plate fixedly arranged on the valve head stator. The liquid passing channel extends axially and forms a liquid passing hole on the liquid passing plate. Second bosses surrounding the liquid passing channel are provided on the two end faces of the valve head stator opposite to the liquid passing plate and on the end face of the liquid passing plate facing the top end cover. The valve head stator, the liquid passing plate and the top end cover are abutted against each other through the second bosses to seal the liquid passing channel. Preferably, the surface roughness of the first boss is not greater than Ra0.2μm, and the flatness is not greater than 0.05㎜; preferably, the surface roughness of the second boss is not greater than Ra0.2μm, and the flatness is not greater than 0.05㎜.

[0011] On the basis of the above technical solution, it further includes a pressing piece. The liquid passing channel extends outwards to form a convex portion. The pressing piece is sleeved outside the convex portion and fixedly connected to the valve head stator. The liquid passing channel forms a liquid passing hole on the convex portion, and the liquid passing hole has an angle that inclines outwards from the inside to the outside.

[0012] On the basis of the above technical solution, it further includes an adjusting component, an elastic component and a thrust bearing. A shaft rod extends outwards at the second end of the valve body away from the valve head stator. The thrust bearing is sleeved in the shell, and the moving ring of the thrust bearing presses the elastic component against the stop surface at the shaft rod of the valve body; the adjusting component is sleeved outside the shaft rod and is connected to the shell in an axially adjustable manner. The adjusting component is designed to press the thrust bearing towards the valve head stator end.

[0013] On the basis of the above technical solution, it further includes a sieve plate. The sieve plate shields the inlet and outlet of the suppression passage to prevent the exchange resin from overflowing outwards.

[0014] On the basis of the above technical solution, a degassing component is further provided between the suppressor and the conductivity detector to remove the gas generated after the mobile phase flows through the suppressor.

[0015] Beneficial effects The structure of the present invention is reasonable and includes an injection valve, a chromatographic column, a suppressor and a conductivity detector connected in sequence through pipelines; a degassing component is further provided between the suppressor and the conductivity detector. When gas is generated after the mobile phase flows through the suppressor, it can be discharged outwards through the degassing component, which is beneficial to further reduce the background conductivity filter and improve the ion detection sensitivity. For example, when the mobile phase of the carbonate system flows through the suppressor filled with acidic exchange resin, the generated carbon dioxide can be removed.

[0016] In the present invention, a plurality of suppression passages are formed in the valve core of the suppressor. When the valve core rotates under the action of an external driving unit, different suppression passages can be selectively communicated with the flow-through passages on the valve head stator. In this way, when one suppression passage is working, another suppression passage is regenerated, and the third suppression passage is flushed with ultrapure water for balancing. Thus, the valve core rotates directionally, and a plurality of suppression passages work in sequence, ensuring the continuous progress of ion chromatography analysis and greatly improving the analysis and detection efficiency.

[0017] In the present invention, the suppression passages in the valve core are arranged in a U shape, which is beneficial to achieving a compact volume of the valve core. In addition, the flow channel of the suppression passage is arranged in a U shape. On the one hand, in a high-pressure environment where the mobile phase has a high pressure and high concentration, the bottom of the U shape can well support the exchange resin, enabling the exchange resin to effectively buffer the mobile phase, making the mobile phase fully contact the exchange resin, and improving the separation effect. On the other hand, the high-pressure mobile phase after buffering can reduce the extrusion effect on the exchange resin, which is beneficial to maintaining the effective porosity and functional group activity of the exchange resin and further improving the separation effect. On the further hand, the mobile phase after buffering can flow through the suppression passage more evenly, which is beneficial to improving the suppression effect. On the still further hand, the fluid passage is formed in the valve core, with excellent high-pressure resistance performance, which can be applied to more complex scenarios. At the same time, the structure is simplified, and the risk of leakage failure is reduced.

[0018] In the valve core of the present invention, a top end cover, a core body, and a bottom end cover are sleeved inside the valve body, and they jointly form the suppression passage. Moreover, between the top end cover, the core body, and the bottom end cover, and between the top end cover and the liquid-passing plate, they are abutted through the first boss, greatly reducing the processing technology difficulty and manufacturing cost, and ensuring good fitting accuracy. Moreover, it is beneficial to improve the sealing reliability and pressure resistance performance. In addition, between the valve head stator and the liquid-passing plate, and between the liquid-passing plate and the top end cover, they are abutted through the second boss, which can also reduce the processing technology difficulty and manufacturing cost, is beneficial to improving the sealing reliability and pressure resistance performance, and can be applied to a high-pressure environment.

[0019] In addition, the contact between the end faces of the valve core and the liquid-passing plate, and the setting of the adjusting component can enable the valve core and the valve head stator to continue to maintain a pressed state after wear, greatly extending the service life. The setting of the elastic component can enable the valve core and the valve head stator to always maintain a pressed state during the working state, which is beneficial to improving the sealing reliability and pressure resistance performance to be applicable to a high-pressure environment. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the following-described drawings are only one embodiment of the present invention. For those of ordinary skill in the art, without creative efforts, other implementation drawings can be obtained according to the provided drawings.

[0021] Figure 1 : Schematic diagram of the process of the present invention; Figure 2 : Three-dimensional structure schematic diagram of the suppressor in the present invention; Figure 3 : Three-dimensional structure schematic diagram of the suppression path formed by the top end cover, core body and bottom end cover in the suppressor; Figure 4 : Figure 2 Structural schematic diagram of the top view of the suppressor in; Figure 5 : Figure 4 Structural schematic diagram of the sectional view taken along the line B-B in; Figure 6 : Figure 5 Local enlarged structural schematic diagram at position A in; Specific implementation manners The following description and drawings fully illustrate the specific embodiments herein, enabling those skilled in the art to practice them. Parts and features of some embodiments may be included in or substituted for parts and features of other embodiments. The scope of the embodiments herein includes the entire scope of the claims and all available equivalents of the claims. Herein, the terms "first", "second", etc. are only used to distinguish one element from another, without requiring or implying any actual relationship or order between these elements. In fact, the first element can also be called the second element, and vice versa. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a structure, device or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such structure, device or equipment. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the structure, device or equipment including the said element. The embodiments herein are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other.

[0022] As used herein, the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In the description of the present invention, unless otherwise specified and defined, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, they can be mechanical connections or electrical connections, or the communication inside two elements. They can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0023] As used herein, unless otherwise specified, the term "a plurality of" means two or more.

[0024] As used herein, the character " / " indicates that the objects before and after are in an "or" relationship. For example, A / B means: A or B.

[0025] As used herein, the term "and / or" is an associative relationship describing an object, indicating that three relationships can exist. For example, A and / or B means: A or B, or, the three relationships of A and B.

[0026] As Figures 1 - 6 shown, an ion chromatography suppression system includes an injection valve 10, a chromatographic column 20, a suppressor 30, a degassing assembly, and a conductivity detector 40 that are sequentially connected through pipelines; The injection valve 10 is a prior art and can be respectively connected to the sample solution and the mobile phase to complete the injection. Specifically, the injection valve 10 includes a sample loading position and an injection position. The sample loading position is connected to the mobile phase source through a plunger pump, so that the plunger pump can supply the mobile phase to the injection valve 10. Injection can be performed using an automatic injector or manually. In this embodiment, injection is performed using an automatic injector, and the automatic injector supplies the sample to the injection position of the injection valve 10, thus completing the injection operation.

[0027] The chromatographic column 20 is a prior art and is used to separate the ion components in the sample solution from each other; The suppressor 30 is used to reduce the background conductivity in the mobile phase; The degassing assembly includes a degasser, and the degasser is used to remove the gas generated after the mobile phase flows through the suppressor. Among them, the degasser is a prior art, and those skilled in the art can select it according to needs and will not be elaborated here.

[0028] The conductivity detector 40 measures the conductivity of the mobile phase and the sample solution flowing through the suppressor to calculate the concentration of each ion in the sample solution.

[0029] As shown Figure 2 in FIG. 1, the suppressor includes a housing 1 and a valve head stator 2. The housing 1 is made of stainless steel, and a valve core 3 is rotatably connected inside the housing 1.

[0030] As shown Figure 3 in FIGS. 2 5 and 3, a plurality of suppression passages 100, 200, 300 are formed circumferentially inside the valve core 3. Specifically, the valve core 3 includes a valve body 31. A core body 312 is sleeved inside the valve body 31, and a top end cover 311 and a bottom end cover 313 are respectively arranged at both ends of the core body 312. The core body 312, the top end cover 311 and the bottom end cover 313 together form a plurality of suppression passages 100, 200, 300. In this embodiment, there are three suppression passages 100, 200, 300, and they are circumferentially and evenly arranged. The suppression passages 100, 200, 300 are used to fill with suppression exchange resin. The suppression passages 100, 200, 300 are U-shaped and form inlets 101, 201, 301 and outlets 102, 202, 302 on the top end cover, as shown Figure 2 in FIG. 4; In this embodiment, the core body 312 is connected to the valve body 31 by keys. There are three keys and they are circumferentially and evenly arranged. The outer wall surface of the core body 312 is a stepped surface. The length section of the core body 312 with a larger outer diameter is in interference fit with the valve body 31, and the top end cover 311 and the bottom end cover 313 are in clearance fit with the valve body 31. In this way, it is not only convenient for the processing of the top end cover 311, the core body 312 and the bottom end cover 313, but also convenient to sleeve the core body 312, the top end cover 311 and the bottom end cover 313 inside the valve body 31.

[0031] In addition, in order to ensure good position accuracy of the core body 312, the top end cover 311 and the bottom end cover 313, the top end cover 311 and the core body 312 are positioned by a plurality of axially arranged first positioning posts 314. Grooves for accommodating the first positioning posts 314 are provided at corresponding positions of the top end cover 311 and the core body 312. The bottom end cover 313 and the core body 312 are positioned by a plurality of axially arranged second positioning posts 315. Grooves for accommodating the second positioning posts 315 are provided at corresponding positions of the bottom end cover 313 and the core body 312.

[0032] As shown Figure 5 in FIG. 5, threaded holes are provided on the bottom surface of the core body 312, and through holes are provided at corresponding positions of the bottom end cover 313. A screw can pass through the through hole and be screwed with the core body 312 to fix the bottom end cover 313 and the core body 312 in this way, and at the same time make the two have a certain pressing force to ensure the sealing performance.

[0033] As shown Figure 5 in FIGS. 6 6As shown, the suppression passages 100, 200, and 300 form stepped holes on the top end cover 311, form through holes with equal diameters on the core body 312, and form long grooves on the bottom end cover 313. A plurality of long grooves are circumferentially and evenly arranged, thus forming the three U-shaped suppression passages 100, 200, and 300, which are convenient for processing and forming, and are beneficial to improving the processing accuracy of the suppression passages 100, 200, and 300.

[0034] As Figure 6 shown, on the end faces where the top end cover 311, the core body 312, and the bottom end cover 313 face each other pairwise, and on the end face of the top end cover 311 facing the valve head stator 2, there are all first bosses 9 arranged around the suppression passages 100, 200, and 300. The valve head stator 2, the top end cover 311, the core body 312, and the bottom end cover 313 are in abutment with each other through the first bosses 9 pairwise to seal the suppression passages well and have relatively high high-pressure resistance performance, which can greatly reduce the processing technology difficulty and cost.

[0035] As Figure 5 shown, a first bearing 17 is sleeved on the first end of the valve body 31, and the valve body 31 is rotationally connected to the housing 1 through the first bearing 17. A second bearing 18 is sleeved on the second end of the valve body 31, the second bearing 18 is embedded in the abutment sleeve 19, and the abutment sleeve 19 is sleeved in the housing 1. Thus, the second end of the valve body 31 is rotationally connected to the housing 1 through the second bearing 18. The settings of the first bearing 17 and the second bearing 18 are beneficial to ensuring the smooth and continuous rotation of the valve body 31.

[0036] In this embodiment, a shaft rod extends outward at the second end of the valve body 31 away from the valve head stator 2, and the shaft rod can be connected to the output shaft of the external drive unit 4 through a coupling 15. As Figure 1 shown, it further includes a bracket 16, and the housing 1 and the drive unit 4 are respectively fixed on the opposite end faces of the bracket 16, which is convenient for installation and arrangement.

[0037] The valve head stator 2 is fixed on the housing 1 through a plurality of bolt assemblies and is provided with a plurality of flow-through passages 400 that can be respectively communicated with the inlets 101, 201, 301 and the outlets 102, 202, 302 of the suppression passages 100, 200, 300; when the valve core 3 rotates directionally relative to the valve head stator 2 under the action of the external drive unit 4, the suppression passages 100, 200, 300 can work in sequence. Specifically, the drive unit 4 drives the valve core 3 to rotate clockwise, so that the first suppression passage 100 works. At this time, another suppression passage 200 is regenerated, and at this time, the third suppression passage 300 is flushed with ultrapure water to balance. In this way, the valve core 3 rotates directionally, and the plurality of suppression passages 100, 200, 300 work in sequence, which can ensure the continuous progress of ion chromatography analysis and greatly improve the analysis and detection efficiency.

[0038] In this embodiment, it further includes a liquid passing plate 12 and a pressing plate 14. The liquid passing plate 13 is fixedly arranged on the valve head stator 2 and is arranged close to one side of the valve core 3. The liquid passing passage 400 extends axially and forms a liquid passing hole 120 on the liquid passing plate 12. Second bosses 13 surrounding the liquid passing passage 400 are provided on the two opposite end faces of the valve head stator 2 and the liquid passing plate 12, and on the end face of the liquid passing plate 12 facing the top end cover 311. In this way, the valve head stator 2, the liquid passing plate 12, and the top end cover 311 are abutted against each other through the second bosses 13 to seal the liquid passing passage 400, with good high-pressure resistance performance, which can greatly reduce the processing technology difficulty and cost.

[0039] As Figure 5 shown, the liquid passing passage 400 extends outwards to form a convex part, and identifiers for identifying the respective suppression passages 100, 200, and 300 are provided on the convex part, which is convenient for identifying the respective suppression passages 100, 200, and 300; the pressing plate 14 is sleeved outside the convex part and is fixedly connected to the valve head stator 2. The liquid passing passage 400 forms a liquid passing hole on the convex part, and the liquid passing hole has an angle that slopes outwards from the inside to the outside, so as to facilitate connection with other passages.

[0040] As Figure 5 shown, it further includes an adjusting component 5. In this embodiment, the adjusting component 5 includes a nut sleeved outside the shaft rod. The end of the nut extends into the housing 1 and abuts against the outer end face of the abutting sleeve 19, and the head end of the nut extends out of the housing 1. In this way, the adjusting component 5 is axially position-adjustably connected to the housing 1, and the adjusting component 5 presses the valve core 3 against the valve head stator 2. When the top end cover 311 or the liquid passing plate 12 is worn, the staff can manually rotate the nut to press the top end cover 311 and the liquid passing plate 12 against each other and maintain sufficient pressing force to cope with the high-pressure use environment.

[0041] As Figure 5 shown, it further includes an elastic component 6 and a thrust bearing 7 arranged close to the adjusting component 5. The thrust bearing 7 is sleeved in the housing 1. The outer wall surface of the valve body 31 is stepped, and the formed shaft shoulder constitutes a stop surface. The fixed ring of the thrust bearing 7 abuts against the inner end face of the abutting sleeve 19, and the moving ring of the thrust bearing 19 presses the elastic component 6 against the stop surface. In this embodiment, the elastic component 6 is a plurality of compression springs sleeved outside the valve body 31. In this way, it can be ensured that under the working state and in the case of continuous wear of the top end cover 311 and the liquid passing plate 12, the top end 311 is always pressed against the liquid passing plate 12, so as to ensure a good sealing effect.

[0042] As Figure 6As shown, it further includes a sieve plate 8, which shields the inlets 101, 201, 301 and outlets 102, 202, 302 of the suppression passages 100, 200, 300 to prevent the exchange resin from overflowing outward. The sieve plate 8 is a prior art, and those skilled in the art can select it according to requirements. The filtration aperture of the sieve plate 8 is smaller than the molecular particle size of the exchange resin.

[0043] Working process As Figure 1 shown, first, under the cooperation of the mobile phase plunger pump and the sampling peristaltic pump of the injector, sampling is completed. This is a prior art and will not be elaborated here. After that, the mobile phase pushes the sample liquid forward through the chromatographic column to separate the ionic components in the sample liquid from each other. After that, the mobile phase continues to push the sample liquid forward through the suppression passage 100 of the suppressor to reduce the background conductivity in the mobile phase. At this time, the inlet 201 of the suppression passage 200 is connected to the flushing liquid. Under the action of the flushing peristaltic pump, the flushing liquid flows through the suppression passage 200 and flows out from the outlet 202, and the waste liquid is discharged. In other embodiments of the present application, the inlet 201 of the suppression passage 200 can also be connected to the waste liquid port of the conductivity detector, and the liquid after the sample liquid and the mobile phase flow through the conductivity detector is used as the flushing liquid (as Figure 1 shown by the dotted line flow path in the middle); at this time, the inlet 301 of the suppression passage 300 is connected to the regeneration liquid. Under the action of the regeneration peristaltic pump, the regeneration liquid flows through the suppression passage 300 and flows out from the outlet 302, and the waste liquid is discharged.

[0044] After that, the mobile phase continues to push the sample liquid forward through the degassing component and then enters the conductivity detector to complete the detection.

[0045] After that, the conductivity detector measures the conductivity of the mobile phase and the sample liquid flowing through the suppressor to calculate the concentration of each ion in the sample liquid.

[0046] The present invention has been described by way of example above, but the present invention is not limited to the above specific embodiments. Any modification or variation based on the present invention falls within the scope of protection required by the present invention.

Claims

1. An ion chromatography suppression system, characterized in that, It includes an injection valve (10), a chromatographic column (20), a suppressor (30), and a conductivity detector (40) that are connected in sequence through pipelines; The injection valve (10) can be respectively connected to the sample liquid and the mobile phase to complete sample injection; The chromatographic column (20) is used to separate the ionic components in the sample liquid from each other; The suppressor (30) is used to reduce the background conductivity in the mobile phase. The suppressor (30) includes a housing (1) and a valve head stator (2). A valve core (3) is rotatably connected in the housing (1). A plurality of suppression channels (100, 200, 300) arranged circumferentially are formed in the valve core (3). The suppression channels (100, 200, 300) are used to fill the exchange resin for suppression. The suppression channels (100, 200, 300) are U-shaped and form inlets (101, 201, 301) and outlets (102, 202, 302) on the end face of the valve core (3). The valve head stator (2) is fixedly arranged on the housing (1) and is provided with a plurality of flow-through channels (400) that can be respectively communicated with the inlets (101, 201, 301) and outlets (102, 202, 302) of the suppression channels (100, 200, 300). When the valve core (3) rotates relative to the valve head stator (2) under the action of an external driving unit (4), a plurality of suppression channels (100, 200, 300) can work in sequence. The conductivity detector (40) measures the conductivity of the mobile phase and the sample liquid flowing through the suppressor to calculate the concentration of each ion in the sample liquid.

2. The suppression system for ion chromatography according to claim 1, wherein The valve core (3) includes a valve body (31). A core body (312) is sleeved in the valve body (31), and a top end cover (311) and a bottom end cover (313) are respectively arranged at both ends of the core body (312). The core body (312), the top end cover (311), and the bottom end cover (313) jointly form a plurality of suppression channels (100, 200, 300); the suppression channels (100, 200, 300) form stepped holes on the top end cover (311), the suppression channels (100, 200, 300) form through holes on the core body (312), and the suppression channels (100, 200, 300) form long grooves on the bottom end cover (313).

3. The suppression system for ion chromatography according to claim 2, wherein, The core body (312) is in interference fit with the valve body (31), the top end cover (311) and the bottom end cover (313) are in clearance fit with the valve body (31). The top end cover (311) and the core body (312) are positioned by a plurality of axially arranged first positioning columns, the bottom end cover (313) and the core body (312) are positioned by a plurality of axially arranged second positioning columns, and the top end cover (311), the core body (312), and the bottom end cover (313) are axially pressed on the valve head stator (2).

4. The suppression system for ion chromatography according to claim 3, wherein On the end faces of the top end cap (311), the core body (312), and the bottom end cap (312) that face each other in pairs, and on the end face of the top end cap (311) facing the valve head stator (2), there are first bosses (9) arranged around the suppression passages (100, 200, 300). The valve head stator (2), the top end cap (311), the core body (312), and the bottom end cap (313) are abutted against each other through the first bosses (9) in pairs to seal the suppression passages (100, 200, 300).

5. The suppression system for ion chromatography according to claim 4, wherein, On the end face of the valve head stator (2) facing the top end cap (311), there is a second boss (13) arranged around the flow-through passage (400). The valve head stator (2) and the top end cap (311) are abutted against each other through the second boss (13) in pairs to seal the flow-through passage (400).

6. The suppression system for ion chromatography according to claim 5, wherein, It further includes a liquid passing plate (12) fixedly arranged on the valve head stator (2). The flow-through passage (400) extends axially and forms a liquid passing hole (120) on the liquid passing plate (12). On the two end faces of the valve head stator (2) opposite to the liquid passing plate (12) and on the end face of the liquid passing plate (12) facing the top end cap (311), there are second bosses (13) arranged around the flow-through passage (400). The valve head stator (2), the liquid passing plate (12), and the top end cap (311) are abutted against each other through the second bosses (13) in pairs to seal the flow-through passage (400).

7. The suppression system for ion chromatography according to claim 6, wherein, It further includes a pressing plate (14). The flow-through passage (400) extends outward to form a convex portion. The pressing plate (14) is sleeved outside the convex portion and fixedly connected to the valve head stator (2). The flow-through passage (400) forms a flow-through hole on the convex portion, and the flow-through hole has an angle that slopes outward from the inside to the outside.

8. The suppression system for ion chromatography according to any one of claims 2 to 7, characterized in that, It further includes an adjusting assembly (5), an elastic assembly (6), and a thrust bearing (7). A shaft rod extends outward at the second end of the valve body (31) away from the valve head stator (2). The thrust bearing (7) is sleeved inside the housing (1), and the moving ring of the thrust bearing (7) presses the elastic assembly (6) against the stop surface at the shaft rod of the valve body (31). The adjusting assembly (5) is sleeved outside the shaft rod and is connected to the housing (1) in an axially adjustable manner. The adjusting assembly (5) is designed such that the adjusting assembly (5) presses the thrust bearing (7) toward the valve head stator end (2).

9. The suppression system for ion chromatography according to claim 8, wherein, It further includes a sieve plate (8). The sieve plate (8) shields the inlets (101, 201, 301) and outlets (102, 202, 302) of the suppression passages (100, 200, 300) to prevent the exchange resin from overflowing outward.

10. The suppression system for ion chromatography according to claim 8, characterized in that, A degassing assembly is further provided between the suppressor (30) and the conductivity detector (40) to remove the gas generated after the mobile phase flows through the suppressor (30).

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