An ion chromatography (IC) suppressor includes a first clamping plate, an intermediate plate, a second clamping plate, a first ion exchange membrane, a second ion exchange membrane, a first electrode and a second electrode. The first clamping plate, the intermediate plate and the second clamping plate are tightly buckled in sequence to compact the first ion exchange membrane between the first clamping plate and the intermediate plate and compact the second ion exchange membrane between the intermediate plate and the second clamping plate. Resin particles are filled between the two ion exchange membranes. An eluent inlet and an eluent outlet are provided respectively at two ends of the intermediate plate, and an accommodating groove is formed at each of a tail end of the eluent inlet and a head end of the eluent outlet. The first clamping plate and the second clamping plate are provided with a sealing lip, respectively.

CROSS REFERENCE TO THE RELATED APPLICATIONS

This application is the national phase entry of International Application No. PCT/CN2020/139994, filed on Dec. 28, 2020, which is based upon and claims priority to Chinese Patent Application No. 202010062988.X, filed on Jan. 20, 2020, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to the field of ion chromatography (IC), and more particularly, to an IC suppressor.

BACKGROUND

In ion chromatography (IC), a suppressor plays the main roles of reducing the background conductance of a mobile phase, increasing the conductance response of an ion to be tested, and the like, which makes the IC technology truly become an effective ion analysis means. Therefore, the suppressor is one of the key components for IC. Packed column suppressors, fiber suppressors, and micro-membrane suppressors were used early, and suppressors currently used combine a membrane technology and an electrochemical technology. The prior suppressors, however, mainly have the shortcomings of low pressure resistance and easy leakage, so that the prior suppressors need to be frequently maintained, and also need to be rinsed once a week or two to make the suppressors wet. In addition, the prior suppressors involve complicated assembly and difficult consistency control.

When the prior suppressor is internally packed with resin particles to control a dead volume, a pore size of an eluent inlet or outlet is generally required to be less than 50 μm, namely, smaller than a particle size of the internally packed particles, which will make the inlet or outlet of an eluent channel slender and thus results in high processing requirements, low yield rate, and high cost. Moreover, the particle size of the packed particles cannot completely be controlled within a preset particle size range, and the packed particles may also be broken during use, which may block the inlet and outlet and thus causes an increase in a pressure of a suppressor. In addition, a mesh screen suppressor is also used. The mesh screen structure used during processing is obtained by processing a conductive and corrosion-resistant material into a mesh structure, which involves stringent material selection and processing requirements.

SUMMARY

An objective of the present invention is to provide an IC suppressor to solve the existing technical problems in the above-mentioned background art.

In order to solve the above technical problems, the present invention provides the following technical solution: An IC suppressor is provided, including a first clamping plate, an intermediate plate, a second clamping plate, a first ion exchange membrane, a second ion exchange membrane, a first electrode and a second electrode, where the first clamping plate, the intermediate plate and the second clamping plate are tightly buckled in sequence to compact the first ion exchange membrane between the first clamping plate and the intermediate plate and compact the second ion exchange membrane between the intermediate plate and the second clamping plate; a suppression chamber is formed between the first ion exchange membrane and the second ion exchange membrane, and the suppression chamber is filled with resin particles for ion exchange and support; the first electrode is embedded on a side of the first clamping plate adjacent to the intermediate plate, and a first electrolysis chamber is formed between the first electrode and the first ion exchange membrane; the second electrode is embedded on a side of the second clamping plate adjacent to the intermediate plate, and a second electrolysis chamber is formed between the second electrode and the second ion exchange membrane; the first ion exchange membrane and the second ion exchange membrane separate the suppression chamber, the first electrolysis chamber, and the second electrolysis chamber into three independent chambers; an eluent inlet and an eluent outlet are provided respectively at two ends of the intermediate plate, and an accommodating groove for mounting a screen plate is formed at each of a tail end of the eluent inlet and a head end of the eluent outlet; a first electrolyte inlet and a first electrolyte outlet are formed on a side of the first clamping plate away from the intermediate plate; and a second electrolyte inlet and an exhaust gas-liquid outlet are formed on a side of the second clamping plate away from the intermediate plate.

On the basis of the above technical solution, the screen plate may be provided at each of a tail end of the first electrolyte inlet, a head end of the first electrolyte outlet, a tail end of the second electrolyte inlet, and a head end of the exhaust gas-liquid outlet.

On the basis of the above technical solution, the screen plate may be made from polyethylene (PE).

On the basis of the above technical solution, the side of the first clamping plate adjacent to the intermediate plate and the side of the second clamping plate adjacent to the intermediate plate may be respectively provided with a sealing lip for sealing and separation, and the first ion exchange membrane and the second ion exchange membrane may be respectively adapted to the sealing lip.

On the basis of the above technical solution, a groove may be formed on the intermediate plate, a shape of the groove may be adapted to a shape of the first ion exchange membrane, and the groove is configured to mount and position the first ion exchange membrane.

On the basis of the above technical solution, each of the first electrode and the second electrode may be a titanium electrode, and a surface of the titanium electrode may be coated with a corrosion-resistant inert metal.

On the basis of the above technical solution, the first electrolysis chamber and the second electrolysis chamber may be filled with the resin particles for support and diversion.

On the basis of the above technical solution, an outer side of the first clamping plate and an outer side of the second clamping plate may be provided with a first pressing plate and a second pressing plate, respectively; and the first pressing plate and the second pressing plate may be connected through a bolt.

On the basis of the above technical solution, an outer side of the first pressing plate and an outer side of the second pressing plate may be provided with a first housing and a second housing, respectively; and the first housing and the second housing may be buckled to package the first pressing plate, the first clamping plate, the first electrode, the first ion exchange membrane, the intermediate plate, the second ion exchange membrane, the second electrode, the second clamping plate, and the second pressing plate.

On the basis of the above technical solution, the eluent outlet may be connected to a conductivity cell; an outlet of the conductivity cell may be connected to the first electrolyte inlet; and the first electrolyte outlet may be connected to the second electrolyte inlet through a hose.

The technical solutions provided by the present invention have the following beneficial effects:

1. Resin particles are filled between the two ion exchange membranes. On the one hand, the resin particles can support the two ion exchange membranes to avoid collapse and bulging, which may cause an incomplete suppression reaction and thus affects a peaking effect of a chromatogram. On the other hand, the resin particles enable ion exchange to make a reaction complete and a suppression complete.

2. A screen plate is provided at each of a tail end of the eluent inlet and a head end of the eluent outlet, which can effectively retain the resin particles in the suppression chamber, and is suitable for the situation where the eluent inlet and outlet have a large pore size, thereby reducing the processing difficulty of the eluent inlet and outlet channels.

3. The first clamping plate and the second clamping plate are respectively provided with a sealing lip adapted to the first ion exchange membrane and the second ion exchange membrane, which plays a sealing role and avoids liquid leakage.

4. Resin particles are filled inside the first electrolysis chamber and the second electrolysis chamber, which support the ion exchange membranes and can also guide a regeneration solution.

5. A groove is formed on the intermediate plate to facilitate the mounting and positioning of the first ion exchange membrane and make the overall assembly easy and convenient.

6. The eluent outlet is connected to a conductivity cell, and water produced by the conductivity cell enters the first electrolysis chamber and the second electrolysis chamber, thereby realizing the regenerative recycling of an electrolyte in the suppressor device.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention is described in further detail below with reference to the accompanying drawings and embodiments:

In the present invention, unless otherwise specified and defined, the terms such as “connected to”, “connected with”, and “fixed” should be comprehended in a broad sense. For example, these terms may be comprehended as being fixedly connected, removably connected, or integrally connected; may be comprehended as being directly connected, or indirectly connected through an intermediate medium; and may be comprehended as being in an internal communication between two elements or an interactive relationship between two elements. Those of ordinary skill in the art may understand specific meanings of the above terms in the present invention based on a specific situation.

In the description of the present invention, it should be understood that orientations or position relationships indicated by terms “left”, “right”, “front”, “rear”, “top”, “bottom”, and the like are orientation or position relationships as shown in the drawings, and these terms are just used to facilitate description of the present invention and simplify the description, but not to indicate or imply that the mentioned device or elements must have a specific orientation and must be established and operated in a specific orientation. Therefore, these terms cannot be understood as a limitation to the present invention.

As shown inFIG.1toFIG.8, an IC suppressor is provided, including a first clamping plate1, an intermediate plate2, a second clamping plate3, a first ion exchange membrane4, a second ion exchange membrane5, a first electrode7and a second electrode9. The first clamping plate1, the intermediate plate2and the second clamping plate3are tightly buckled in sequence to compact the first ion exchange membrane4between the first clamping plate1and the intermediate plate2and compact the second ion exchange membrane5between the intermediate plate2and the second clamping plate3. A suppression chamber6is formed between the first ion exchange membrane4and the second ion exchange membrane5, and the suppression chamber6is filled with resin particles for supporting and controlling a dead volume. More preferably, the suppression chamber6may have a length of 5.0 cm to 10.0 cm, a width of 0.5 cm to 1.0 cm, and a thickness of 0.3 cm to 1.0 mm.

The resin particles filled inside the suppression chamber6have electric conductivity. On the one hand, the resin particles can support the two ion exchange membranes to avoid collapse and bulging, which may cause an incomplete suppression reaction and thus affects a peaking effect of a chromatogram. On the other hand, the resin particles enable ion exchange to make a reaction complete and a suppression complete. By controlling a quantity of resin particles filled inside the suppression chamber, the dead volume in the suppression chamber can be controlled within an appropriate range, such that each ion peak on an ion chromatogram obtained has the characteristics of high signal, small peak width, and prominent resolution, which is convenient for the staff to analyze and process a chromatogram. If there are too few resin particles filled in the suppression chamber, the dead volume is too large, which is easy to cause poor resolution and makes a peak of each ion on an ion chromatogram not easily observed and distinguished. If there are too many resin particles filled in the suppression chamber, the dead volume is too small, which will cause an internal pressure of the suppressor to be high and thus makes the ion exchange membrane prone to burst and other undesirable phenomena.

As shown inFIG.2andFIG.3, the first electrode7is embedded on a side of the first clamping plate1adjacent to the intermediate plate2, and a first electrolysis chamber8is formed between the first electrode7and the first ion exchange membrane4. The second electrode9is embedded on a side of the second clamping plate3adjacent to the intermediate plate2, and a second electrolysis chamber10is formed between the second electrode9and the second ion exchange membrane5. Each of the first electrode7and the second electrode9is a titanium electrode, and a surface of the titanium electrode is coated with a corrosion-resistant inert metal. More preferably, the inert metal coating on the surface of the titanium electrode may be iridium or ruthenium. The inert metal coating on the electrode can enhance the corrosion resistance of the electrode and prolong the service life of the electrode.

The first ion exchange membrane4and the second ion exchange membrane5separate the suppression chamber6, the first electrolysis chamber8, and the second electrolysis chamber10into three independent chambers. In this way, the problem of interpenetration of an eluent among the various chambers can be avoided, and excellent sealing performance can be achieved. However, it should be noted that the above-mentioned increase in the sealing performance does not affect a normal ion exchange process among the various chambers.

As shown inFIG.5andFIG.6, an eluent inlet11and an eluent outlet12are formed at two ends of the intermediate plate2, and an accommodating groove13for mounting a screen plate14is formed at each of a tail end of the eluent inlet11and a head end of the eluent outlet12. More preferably, the screen plate14may be made from PE. Since a pore size of the eluent inlet11or the eluent outlet12is larger than a particle size of the resin particles (specifically, the pore size of the eluent inlet11or the eluent outlet12is 0.5 mm, and the particle size of the resin particles is 50 μm to 150 μm), a screen plate14is provided at each of a tail end of the eluent inlet11and a head end of the eluent outlet12to effectively retain the resin particles in the suppression chamber6. The accommodating groove13is provided with a screen plate14, which is suitable for the situation where the eluent inlet and outlet have a large pore size, thereby reducing the processing difficulty of the eluent inlet and outlet channels.

As shown inFIG.4andFIG.7, the side of the first clamping plate1adjacent to the intermediate plate2and the side of the second clamping plate3adjacent to the intermediate plate2are respectively provided with a sealing lip15for sealing and separation, and the first ion exchange membrane4and the second ion exchange membrane5are respectively adapted to the sealing lip15. The sealing lip15is provided to seal the first ion exchange membrane4and the second ion exchange membrane5, which can avoid liquid leakage and provide excellent sealing performance.

A first electrolyte inlet16and a first electrolyte outlet17are formed on a side of the first clamping plate1away from the intermediate plate2; and a second electrolyte inlet18and an exhaust gas-liquid outlet19are formed on a side of the second clamping plate3away from the intermediate plate2. An electrolyte enters the first electrolysis chamber8and the second electrolysis chamber10from the first electrolyte inlet16and the second electrolyte inlet18to participate in a suppression reaction, and the electrolyte can enter the electrolysis chamber through an external water pipe or a recycling pipe inside the suppressor.

As shown inFIG.2andFIG.3, an outer side of the first clamping plate1and an outer side of the second clamping plate3are provided with a first pressing plate20and a second pressing plate21, respectively; and the first pressing plate20and the second pressing plate21are connected through a bolt. More preferably, the first pressing plate20and the second pressing plate21may be made of a metal. Since a metal plate has relatively high rigidity, the first clamping plate1and the second clamping plate3are fixedly compacted through surface fitting, which is reliable and can avoid damage to the first clamping plate1and the second clamping plate3inside.

An outer side of the first pressing plate20and an outer side of the second pressing plate21are provided with a first housing22and a second housing23, respectively; and the first housing22and the second housing23are buckled to package the first pressing plate20, the first clamping plate1, the first electrode7, the first ion exchange membrane4, the intermediate plate2, the second ion exchange membrane5, the second electrode9, the second clamping plate3, and the second pressing plate21inside the suppressor. The first pressing plate20, the second pressing plate21, the first housing22, and the second housing23are provided to make the entire suppressor buckled tightly and provide prominent sealing performance.

On the basis of Embodiment 1, as shown inFIG.5, a groove24is formed on the intermediate plate2, a shape of the groove24is adapted to a shape of the first ion exchange membrane4, and the groove24is configured to mount and position the first ion exchange membrane4. A groove24is formed on the intermediate plate2to facilitate the arrangement and fixation of the first ion exchange membrane4. As shown inFIG.4, a protrusion adapted to the groove24is provided on the first clamping plate1and a sealing lip15is provided on the first clamping plate1to seal the first ion exchange membrane4arranged in the groove. As mentioned above, this can facilitate the assembly of the suppressor device, and is more suitable for industrial production and application.

On the basis of Embodiment 2, the first electrolysis chamber8and the second electrolysis chamber10are filled with the resin particles for support and diversion. The resin particles are conductive. The filling of resin particles in the first electrolysis chamber8and the second electrolysis chamber10can support the first ion exchange membrane4and the second ion exchange membrane5and avoid the deformation of the ion exchange membranes and the increase of the dead volume. In addition, the resin particles can also guide an electrolyte and accelerate an electrolysis reaction process.

As shown inFIG.4andFIG.7, more preferably, the screen plate14is provided at each of a tail end of the first electrolyte inlet16, a head end of the first electrolyte outlet17, a tail end of the second electrolyte inlet18, and a head end of the exhaust gas-liquid outlet19. It should be noted that the head end and the tail end here are defined according to a flowing direction of an electrolyte; and a position where the electrolyte flows in is the head end, and a position where the electrolyte flows out is the tail end. The screen plate14is provided mainly to restrict and intercept the resin particles filled in the first electrolysis chamber8and the second electrolysis chamber10, thereby avoiding the loss of the resin particles and the blockage of the inlet and outlet.

In this embodiment, the assembly process and steps of an IC suppressor of the present invention are described, which will not be repeated in other embodiments.

An assembly process of the suppressor includes: 1. the first ion exchange membrane4is arranged into the groove24on the intermediate plate2, a layer of resin particles is coated on the first clamping plate1with the first electrode7, and then the first clamping plate1is buckled into the groove24on the intermediate plate2; 2. resin particles are coated in the suppression chamber6, and then the second ion exchange membrane5is arranged on a side of the intermediate plate2away from the groove24; 3. the second clamping plate3with the second electrode9is coated with a layer of resin particles, and then buckled on a side of the intermediate plate2provided with the second ion exchange membrane5for fixing; 4. The first pressing plate20and the second pressing plate21are fixedly arranged on the outer side of the first clamping plate1and the outer side of the second clamping plate3respectively for compacting and fixing, and then the first housing22and the second housing23are buckled on the outermost side for fixing, thereby completing the assembly of the suppressor device. The assembly method of the suppressor provided in the present invention is simple, involves convenient operations, and is more suitable for industrial production and application.

On the basis of Embodiment 3, as shown inFIG.8, (it should be noted thatFIG.8shows a schematic diagram of the principle of an anion suppressor (as an example)), the eluent outlet12is connected to a conductivity cell25; an outlet of the conductivity cell25is connected to the first electrolyte inlet16; and the first electrolyte outlet17is connected to the second electrolyte inlet18through a hose. After passing through the interior of the suppressor, an eluent flows from the eluent outlet12into the conductivity cell25. The outlet of the conductivity cell25is connected to the first electrolyte inlet16, and after passing through the conductivity cell, an electrolyte flows into the first electrolysis chamber8. Since the first electrolyte outlet17and the second electrolyte inlet18are connected through a hose, after flowing out from the first electrolysis chamber8, the electrolyte flows into the second electrolysis chamber10for an electrolysis reaction, and finally flows out through the exhaust gas-liquid outlet19. The electrolyte obtained at this time can also be referred to as a regeneration solution. This arrangement can realize the automatic regeneration of the suppressor device without an external water pipe for the suppressor, which involves convenient operations and saves water resources.

The basic principles and main features of the present invention and the advantages of the present invention are illustrated and described above. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. The embodiments should be regarded as exemplary and non-limiting in every respect, and the scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of equivalent elements of the claims should be included in the present invention. The reference numeral in the claims should not be considered as limiting the involved claims.

It should be understood that although this specification is described in accordance with the embodiments, not every embodiment includes only an independent technical solution. Such a description is merely for the sake of clarity, and those skilled in the art should take the specification as a whole. The technical solutions in the embodiments can also be appropriately combined to form other implementations which are comprehensible for those skilled in the art.