Dual membrane type eluent generator, and chromatography detection instrument

Abstract

To provide an eluent generator that minimizes a possibility of a mixture of impurity in a detection sample in the eluent generator on ion chromatography.SOLUTION: A dual membrane type eluent generator has: an eluent channel 12 that has a first ion exchange membrane assembly 31 arranged; and a regenerating solution channel 13 that has a second ion exchange membrane assembly 41 including a bipolar membrane arranged, enables a hydrogen ion and a hydroxide ion generated after electrolysis of a regenerating solution located between the bipolar membranes to enter a treating membrane, and enables preventing an impurity ion from passing through the bipolar membrane and entering the eluent channel. The dual membrane type eluent generator uses the bipolar membrane 41 between the regenerating solution channel and the eluent channel to thereby not only provide the eluent channel with the treating hydrogen ion, or hydroxide ion, but also prevent the impurity ion in a regenerating solution from entering the eluent channel, which in turn improves purity of eluent.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to the technical field of analytical instrumentation, and in particular to a twin membrane eluent generator and chromatographic detection instrument. [Background technology]

[0002] Referring to Figures 1 and 2, in a twin-membrane eluent generator known to the present inventor, taking a KOH-type eluent as an example, the eluent generator 5 is divided by a cation exchange membrane 61 and an anion exchange membrane 62 into an eluent flow path 63 and an original solution flow path 64 and a regenerant flow path 65 on either side of the eluent flow path 63.

[0003] The stock solution, KOH, is directly connected to the stock solution flow path 64. The eluent in the eluent flow path 63 is connected to the regenerant flow path 65 after use and becomes the regenerant. + passes through the cation exchange membrane 61 and enters the eluent flow path 63, and in the regenerant flow path 65, OH generated by electrolysis of water is - passes through the anion exchange membrane 62 and enters the eluent flow path 63 . Summary of the Invention [Problem to be solved by the invention]

[0004] The twin-membrane eluent generator utilizes used eluent. However, the used eluent may contain impurity ions from the detection sample. If such impurity ions pass through the ion exchange membrane and re-enter the eluent, the purity of the eluent will be reduced, which will cause problems in the subsequent analysis experiments.

[0005] SUMMARY OF THE DISCLOSURE To ameliorate or overcome at least one of the problems set forth above, the present invention provides a dual membrane eluent generator and chromatographic detection instrument. [Means for solving the problem]

[0006] The twin membrane eluent generator provided in the present embodiment includes a first eluent generator, the first eluent generator comprising: a raw solution flow path through which a raw solution flows that provides anions or cations to an eluent; an elution liquid flow path through which water serving as the eluent flows, the elution liquid flow path and the raw solution flow path being provided with a first ion exchange membrane set including at least one ion exchange membrane which is a cation exchange membrane or an anion exchange membrane, and the cations or anions in the raw solution pass through the first ion exchange membrane set and enter the elution liquid flow path; a regenerant liquid flow path into which the used eluent enters and becomes a regenerant liquid, a second ion exchange membrane set including one bipolar membrane is disposed between the eluent flow path and the regenerant liquid flow path, hydrogen ions or hydroxide ions generated after electrolysis of the regenerant liquid located at the bipolar membrane can enter the corresponding different side of the bipolar membrane, and the bipolar membrane can prevent impurity ions other than the hydrogen ions or hydroxide ions from passing through the bipolar membrane and entering the eluant flow path.

[0007] In at least one embodiment, the second set of ion exchange membranes further comprises at least one cation exchange membrane or anion exchange membrane overlaid with the bipolar membrane.

[0008] In at least one embodiment, one of the positive electrode and the negative electrode is disposed in the raw liquid flow path, and the other is disposed in the regenerant flow path.

[0009] In at least one embodiment, the twin membrane eluent generator further comprises a second eluent generator having an eluent flow path; The eluent flow path of the first eluent generator and the eluent flow path of the second eluent generator are connected, so that the eluent generated in the first eluent generator can be further adjusted.

[0010] In at least one embodiment, the second eluent generator and the first eluent generator are identical in structure; The stock solution flow path of the first eluent generator and the stock solution flow path of the second eluent generator are not connected to each other, and the corresponding stock solutions are supplied to each of them; The regenerant flow path of the first eluent generator and the regenerant flow path of the second eluent generator are connected to each other, The eluent passes through the eluent flow path of the first eluent generator and the eluent flow path of the second eluent generator in sequence, and is then used to become the regenerated liquid, and the regenerated liquid passes through the regenerated liquid flow path of the second eluent generator and the regenerated liquid flow path of the first eluent generator in sequence, and is then discharged as waste liquid.

[0011] In at least one embodiment, both sides of the eluent flow path of the second eluent generator are regenerant flow paths, and the used eluent becomes the regenerant and passes through the regenerant flow paths on both sides of the eluent flow path of the second eluent generator and the regenerant flow path of the first eluent generator, before being discharged as waste liquid.

[0012] In at least one embodiment, the second eluent generator is divided into the eluent flow path and the regenerant flow paths on either side thereof by two sets of the second ion exchange membranes.

[0013] The chromatography detection instrument provided in the embodiment of the present invention comprises the above-mentioned twin membrane eluent generator.

[0014] In at least one embodiment, the chromatography detection instrument further comprises a water source, a pump, a sampler, a column, a suppressor, and a detector; By the action of the pump, water from the water source enters the eluent flow path and becomes the eluent, and the eluent passes through the sampler, the column, the suppressor and the detector before entering the regenerant flow path and becoming the regenerant, and after being electrolyzed, becomes a waste liquid and is discharged from the regenerant flow path.

[0015] In at least one embodiment, the chromatography detection instrument further comprises a stock solution bottle and a stock solution pump; The concentrate pump circulates the concentrate between the concentrate bottle and the concentrate flow path; or The concentrate bottle is directly connected to the concentrate flow path. Effect of the Invention

[0016] The bipolar membrane eluent generator provided by the present invention uses a bipolar membrane between the regenerant flow path and the eluent flow path of the bipolar membrane eluent generator, and generates the corresponding H by electrolysis of the regenerant. + Or OH - In addition, impurity ions in the regenerant can be prevented from entering the eluent flow path, improving the purity of the eluent.

[0017] The chromatography detection instrument provided by the present invention, by being equipped with the above-mentioned twin membrane eluent generator, also has the above-mentioned advantages. [Brief description of the drawings]

[0018] [Figure 1] Schematic diagram of the structure of a chromatographic detection device that includes a twin-membrane eluent generator. [Diagram 2] Figure 1. Schematic diagram of the twin-membrane eluent generator. [Diagram 3] FIG. 2 is a schematic structural diagram of an example of a chromatography detection instrument including a twin membrane eluent generator according to an embodiment of the present invention. [Figure 4] FIG. 2 is a schematic structural diagram of another example of a chromatography detection instrument including a twin membrane eluent generator according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a schematic structural diagram of yet another example of a chromatography detection instrument including a twin membrane eluent generator according to an embodiment of the present invention. [Figure 6] FIG. 2 is a schematic structural diagram of yet another example of a chromatography detection instrument including a twin membrane eluent generator according to an embodiment of the present invention. [Figure 7] FIG. 2 is a principle diagram of a twin-membrane eluent generator according to an embodiment of the present invention. [Figure 8] FIG. 2 is another principle diagram of a twin membrane eluent generator according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, embodiments of the present invention will be described by way of examples with reference to the drawings. Note that these specific descriptions are not intended to list all possible embodiments of the present invention, nor to limit the scope of the present invention, but are intended to teach those skilled in the art how to implement the present invention.

[0020] The bipolar membrane is an ion exchange membrane that is a composite of a positive membrane and a negative membrane and has a special ionic structure that does not allow either anions or cations to pass through. However, under the action of a direct current electric field, the H2O between the composite layers of the negative and positive membranes in the bipolar membrane is converted into H + and OH - and H + and OH - can pass through the positive and negative membranes to enter the corresponding sides of the bipolar membrane. Therefore, by using a bipolar membrane between the regenerant flow path and the eluent flow path of the bipolar membrane generator, H can be generated through the corresponding membrane by electrolysis of the regenerant. + Or OH - This not only provides the eluent flow path with impurity ions, but also prevents impurity ions in the regenerant from entering the eluent flow path.

[0021] The present invention provides a twin membrane eluent generator and chromatographic detection instrument that demonstrates the above concepts.

[0022] Below, some examples of the present invention are provided.

[0023] Example 1 3, Example 1 provides a twin-membrane eluent generator including a first eluent generator 1. The first eluent generator 1 has a raw solution flow path 11, an eluent flow path 12, and a regenerant flow path 13.

[0024] The stock solution in the stock solution flow path 11 provides a desired high concentration of anions or cations, such as potassium ions, to the eluent.

[0025] Water (e.g., pure water) in the eluent flow path 12 becomes an eluent after passing through the eluent flow path 12. A first ion exchange membrane set 3 is disposed between the eluent flow path 12 and the raw solution flow path 11. The first ion exchange membrane set 3 includes at least one ion exchange membrane 31. The ion exchange membrane 31 is a cation exchange membrane or an anion exchange membrane. Cations or anions in the raw solution pass through the first ion exchange membrane set 3 and enter the eluent flow path 12.

[0026] After use, the eluent enters the regenerant flow path 13 to become the regenerant. Between the eluent flow path 12 and the regenerant flow path 13, a second ion exchange membrane set 4 is disposed. The second ion exchange membrane set 4 includes one bipolar membrane 41, and hydrogen ions or hydroxide ions generated after electrolysis of the regenerant facing the bipolar membrane 41 can enter the different side of the corresponding bipolar membrane 41 (hydrogen ions on the side where the cation exchange membrane is located, and hydroxide ions on the side where the anion exchange membrane is located), and the bipolar membrane 41 can prevent impurity ions other than hydrogen ions or hydroxide ions from passing through the bipolar membrane 41 and entering the eluent flow path 12. It can be understood that the use of the eluent may refer to the eluent passing through a device such as a sampler, column, or detector to perform a test operation.

[0027] For example, referring to FIG. 7, if the eluent is required to be, for example, KOH, the ion exchange membrane 31 may be a cation exchange membrane, and the KOH in the raw solution flow path 11 may be a cation exchange membrane. +can pass through the cation exchange membrane and enter the eluent flow path 12. The membrane of the bipolar membrane 41 facing the eluent flow path 12 is a negative membrane, and the water in the bipolar membrane 41 is converted into OH generated after electrolysis. - can pass through the negative membrane and enter the eluent flow path 12, and other impurity ions are prevented from entering the eluent flow path 12, thereby making the eluent purer and less contaminant.

[0028] For example, referring to FIG. 8, if the eluent needs to be, for example, MSA (methanesulfonic acid, chemical formula CH4O3S), the ion exchange membrane 31 may be an anion exchange membrane, and the anions of MSA in the raw solution flow path 11 (MSA in FIG. - The anion of MSA (represents the anion of MSA) can pass through the anion exchange membrane and enter the eluent flow path 12. The membrane of the bipolar membrane 41 facing the eluent flow path 12 is a positive membrane, and the water in the bipolar membrane 41 is converted into H + can pass through the positive membrane and enter the eluent flow path 12, and other impurity ions are prevented from entering the eluent flow path 12, thereby further increasing the purity of the eluent.

[0029] It will be understood that the use of the above ion exchange membranes and eluents are merely exemplary, and the specific types of eluents and ion exchange membranes are not limiting in the present invention.

[0030] 7 and 8, the second ion exchange membrane set 4 may include at least one cation exchange membrane or anion exchange membrane overlapped with the bipolar membrane 41. The first ion exchange membrane set 3 may also be configured by overlapping a plurality of ion exchange membranes 31. It can be understood that the multilayer membrane stack structure contributes to improving the mechanical strength and durability of the membrane.

[0031] Further, referring to FIG. 3, one of the positive electrode and the negative electrode is disposed in the stock solution flow path 11, and the other is disposed in the regenerant flow path 13. The positive electrode and the negative electrode may each be connected to a constant current power source. The specific positions of the positive electrode and the negative electrode are not limited in the present invention, and it can be understood that the positions of the electrodes may be reasonably set based on the type of stock solution and the position of each flow path. By controlling the set current value of the constant current power source, the electrolysis of water and the amount of ion movement can be controlled to control the concentration of the eluent.

[0032] Referring to FIG. 3, the chromatography detection device provided by the present invention may include the twin-membrane eluent generator, a water source 71, a pump 72, a sampler 73, a column 74, a suppressor 75, a detector 76, a stock solution bottle 77, and a stock solution pump 78.

[0033] When the pump 72 is driven, water (e.g., pure water) from the water source 71 enters the eluent flow path 12 and becomes the eluent. The eluent passes through the sampler 73, column 74, suppressor 75, and detector 76 and enters the regenerated liquid flow path 13 to become the regenerated liquid. The regenerated liquid is used for electrolysis and then discharged.

[0034] By driving the stock solution pump 78, the stock solution can be circulated in the stock solution bottle 77 and the stock solution flow path 11, and this circulation causes air bubbles to flow, making it possible to prevent the aggregation of air bubbles from having an effect on electrolysis. Furthermore, compared with the case where stock solution flow paths are provided on both sides of the eluent flow path, the stock solution flow path of this embodiment is relatively short, and the stock solution pump 78 only needs to remove air bubbles from the flow path on one side, so the rotation speed of the stock solution pump 78 can be reduced, and noise can be reduced. For example, the stock solution pump 78 may be a peristaltic pump.

[0035] Example 2 Compared with Example 1 shown in Fig. 3, the twin membrane type eluent generator itself of Example 2 shown in Fig. 4 is not changed. The improvement of Example 2 is in the connection form between the stock solution bottle and the stock solution flow path. Specifically, the stock solution bottle 77 may be directly connected to the stock solution flow path 11, and circulation does not occur in the flow path, and air bubbles in the stock solution flow path 11 enter the stock solution bottle 77 directly or are discharged via the stock solution bottle 77, thereby reducing the number of pumps.

[0036] Examples 3 and 4 5 and 6, the twin membrane eluent generator may further include a second eluent generator 2 having an eluent flow path 22. The eluent flow path 12 of the first eluent generator 1 and the eluent flow path 22 of the second eluent generator 2 are connected to each other, so that the eluent generated in the first eluent generator 1 can be further adjusted.

[0037] In the third embodiment, referring to FIG. 5, the second eluent generator 2 and the first eluent generator 1 have the same structure.

[0038] The stock solution flow path 11 of the first eluent generator 1 and the stock solution flow path 21 of the second eluent generator 2 are not connected to each other, and the corresponding stock solutions are supplied to the first eluent generator 1 and the second eluent generator 2. The stock solutions may be the same in type.

[0039] The regenerant liquid flow path 13 of the first eluent generator 1 and the regenerant liquid flow path 23 of the second eluent generator 2 are connected. The eluent passes through the eluent flow path 12 of the first eluent generator 1 and the eluent flow path 22 of the second eluent generator 2 in this order, and is then used as a regenerant liquid, while the regenerant passes through the regenerant liquid flow path 23 of the second eluent generator 2 and the regenerant liquid flow path 13 of the first eluent generator 1 in this order, and is then discharged as a waste liquid.

[0040] In Example 4, referring to FIG. 6, both sides of the eluent flow path 22 of the second eluent generator 2 are regenerant flow paths 24, and the used eluent becomes the regenerant, and passes through the regenerant flow paths 24 on both sides of the eluent flow path 22 of the second eluent generator 2 and the regenerant flow path 13 of the first eluent generator 1, before being discharged as waste liquid.

[0041] The second eluent generator 2 is divided by two sets of second ion exchange membranes 4 into an eluent flow path 22 and two regenerant flow paths 24 on either side of the eluent flow path 22 .

[0042] In Examples 3 and 4, the second eluent generator 2 can perform secondary adjustment of the eluent, and by controlling the type and concentration of the original solution (Example 3), it is possible to control the degree of water electrolysis by the electrodes and further adjust parameters such as the pH and concentration of the eluent.

[0043] Of course, by connecting more eluent generators and by changing the connection form of the eluent flow paths and regenerant flow paths between the eluent generators, it is possible to expand the scope of use to a wider range of applications.

[0044] The chromatography detection device provided by the present invention may be a liquid phase chromatography detection device, an ion chromatography detection device, or the like.

[0045] The above is a preferred embodiment of the present invention. However, those skilled in the art may make some improvements and modifications without departing from the principles of the present invention. These improvements and modifications should be considered within the technical scope of the present invention. [Explanation of symbols]

[0046] 1 first eluent generator; 11 raw solution flow path; 12 eluent flow path; 13 regenerant flow path; 2 second eluent generator; 21 raw solution flow path; 22 eluent flow path; 23 regenerant flow path; 24 regenerant flow path; 3 first ion exchange membrane set; 31 ion exchange membrane; 4 second ion exchange membrane set; 41 bipolar membrane; 5 Eluent generator; 61 cation exchange membrane; 62 anion exchange membrane; 63 eluent flow path; 64 raw solution flow path; 65 regenerant flow path; 71 water source; 72 pump; 73 sampler; 74 column; 75 suppressor; 76 detector; 77 stock solution bottle; 78 stock solution pump.

Claims

1. 1. A twin membrane eluent generator comprising a first eluent generator, The first eluent generator comprises: a raw solution flow path through which a raw solution flows that provides anions or cations to an eluent; an elution liquid flow path through which water serving as the eluent flows, the elution liquid flow path and the raw liquid flow path being provided with a first ion exchange membrane set including at least one ion exchange membrane which is a cation exchange membrane or an anion exchange membrane, and the cations or anions in the raw liquid pass through the first ion exchange membrane set and enter the elution liquid flow path; A bipolar membrane type eluent generator comprising: a regenerant liquid flow path into which the used eluent enters to become a regenerant liquid, a second ion exchange membrane set including one bipolar membrane is disposed between the eluent flow path and the regenerant liquid flow path, hydrogen ions or hydroxide ions generated after electrolysis of the regenerant liquid located at the bipolar membrane can enter the corresponding different side of the bipolar membrane, and the bipolar membrane can prevent impurity ions other than the hydrogen ions or hydroxide ions from passing through the bipolar membrane and entering the eluent flow path.

2. 2. The twin membrane eluent generator according to claim 1, wherein the second set of ion exchange membranes further comprises at least one cation exchange membrane or anion exchange membrane overlapping the bipolar membrane.

3. 2. The twin membrane eluent generator according to claim 1, wherein one of the positive electrode and the negative electrode is disposed in the raw solution flow path, and the other is disposed in the regenerant flow path.

4. a second eluent generator having an eluent flow path; The twin membrane eluent generator according to claim 1, characterized in that the eluent flow path of the first eluent generator and the eluent flow path of the second eluent generator are connected to each other, thereby making it possible to further adjust the eluent generated in the first eluent generator.

5. the second eluent generator and the first eluent generator are identical in structure; The raw liquid flow path of the first eluent generator and the raw liquid flow path of the second eluent generator are not connected to each other, and the corresponding raw liquids are supplied to each of them; The regenerant flow path of the first eluent generator and the regenerant flow path of the second eluent generator are connected to each other, The twin membrane type eluent generator according to claim 4, characterized in that the eluent is used as the regenerated liquid after passing through the eluent flow path of the first eluent generator and the eluent flow path of the second eluent generator in sequence, and the regenerated liquid is discharged as a waste liquid after passing through the regenerated liquid flow path of the second eluent generator and the regenerated liquid flow path of the first eluent generator in sequence.

6. The twin-membrane eluent generator according to claim 4, characterized in that both sides of the eluent flow path of the second eluent generator are regenerant flow paths, and the used eluent becomes the regenerant, and passes through the regenerant flow paths on both sides of the eluent flow path of the second eluent generator and the regenerant flow path of the first eluent generator, before being discharged as a waste liquid.

7. The twin-membrane eluent generator according to claim 6, characterized in that the second eluent generator is divided into the eluent flow path and the regenerant flow paths on both sides thereof by two sets of the second ion exchange membranes.

8. A chromatography detection instrument comprising a twin membrane eluent generator according to any one of claims 1 to 7.

9. The apparatus further includes a water source, a pump, a sampler, a column, a suppressor, and a detector; The chromatography detection device according to claim 8, characterized in that, by the action of the pump, water from the water source enters the eluent flow path and becomes the eluent, the eluent passes through the sampler, the column, the suppressor and the detector, then enters the regenerant flow path and becomes the regenerant, and after being electrolyzed, becomes a waste liquid and is discharged from the regenerant flow path.

10. Further comprising a concentrate bottle and a concentrate pump; The concentrate pump circulates the concentrate between the concentrate bottle and the concentrate flow path; or 9. The chromatography detection instrument of claim 8, wherein the stock solution bottle is directly connected to the stock solution flow path.

Images