Dual membrane type eluent generator and chromatographic detection apparatus

Abstract

This application provides a dual-membrane eluent generator and a chromatographic detection device. The dual-membrane eluent generator includes a stock solution channel; an eluent channel, with a first ion exchange membrane assembly (including at least one ion exchange membrane) disposed between the eluent channel and the stock solution channel; and a regenerated solution channel, with a second ion exchange membrane assembly (including one bipolar membrane) disposed between the eluent channel and the regenerated solution channel. Hydrogen ions or hydroxide ions generated after electrolysis of the regenerated solution at the bipolar membrane enter different sides of the bipolar membrane, preventing impurity ions from entering the eluent channel through the bipolar membrane. The chromatographic detection device provided in this application includes the aforementioned dual-membrane eluent generator. By applying a bipolar membrane between the regenerated channel and the eluent channel, this application can both provide the eluent channel with the corresponding hydrogen ions or hydroxide ions and prevent impurity ions in the regenerated solution from entering the eluent channel, thereby improving the purity of the eluent.

Description

Technical Field

[0001] This application relates to the field of analytical instrument and equipment technology, and in particular to a dual-film eluent generator and chromatographic detection equipment. Background Technology

[0002] See Figure 1 , Figure 2 In a dual-membrane eluent generator known to the inventors of this application, taking KOH type eluent as an example, the eluent generator 5 is divided into an eluent channel 63 and a raw liquid channel 64 and a regenerated liquid channel 65 on both sides by a cation exchange membrane 61 and an anion exchange membrane 62.

[0003] The KOH used as the raw solution is directly connected to the raw solution channel 64. The eluent in the eluent channel 63 is then connected to the regenerated solution channel 65 as the regenerated solution after subsequent use. K+ in the raw solution channel 64 enters the eluent channel 63 through the cation exchange membrane 61, and OH- generated from the electrolysis of water in the regenerated solution channel 65 enters the eluent channel 63 through the anion exchange membrane 62.

[0004] This dual-membrane eluent generator utilizes used eluent. However, used eluent may contain impurity ions from the test sample. These impurity ions can re-enter the eluent through the ion exchange membrane, resulting in low eluent purity and interfering with subsequent analytical experiments. Summary of the Invention

[0005] In order to improve or solve at least one of the technical problems mentioned in the background art, this application provides a dual-film eluent generator and a chromatographic detection device.

[0006] The dual-film eluent generator provided in the embodiments of this application includes a first eluent generator, which comprises:

[0007] The stock solution channel provides anions or cations to the rinsing solution;

[0008] The rinsing solution channel is used to form the rinsing solution after water passes through it. A first ion exchange membrane group is provided between the rinsing solution channel and the original solution channel. The first ion exchange membrane group includes at least one ion exchange membrane, which is a cation exchange membrane or an anion exchange membrane. The cations or anions in the original solution enter the rinsing solution channel through the first ion exchange membrane group.

[0009] The regenerated liquid channel is used to process the rinsing liquid, which then enters the regenerated liquid channel to become the regenerated liquid. A second ion exchange membrane assembly is provided between the rinsing liquid channel and the regenerated liquid channel. The second ion exchange membrane assembly includes a bipolar membrane. Hydrogen ions or hydroxide ions generated after electrolysis of the regenerated liquid at the bipolar membrane can enter different sides of the bipolar membrane. The bipolar membrane can prevent impurity ions other than hydrogen ions or hydroxide ions from entering the rinsing liquid channel through the bipolar membrane.

[0010] In at least one embodiment, the second ion exchange membrane assembly further includes at least one cation exchange membrane or anion exchange membrane superimposed on the bipolar membrane.

[0011] In at least one embodiment, one of the positive electrode and the negative electrode is placed in the raw liquid channel, and the other of the positive electrode or the negative electrode is placed in the regenerated liquid channel.

[0012] In at least one embodiment, the dual-film eluent generator further includes a second eluent generator, the second eluent generator including an eluent channel.

[0013] The rinsing fluid channel of the first rinsing fluid generator is connected to the rinsing fluid channel of the second rinsing fluid generator, so that the rinsing fluid generated by the first rinsing fluid generator can be further adjusted.

[0014] In at least one embodiment, the second rinse fluid generator has the same structure as the first rinse fluid generator.

[0015] The raw material channel of the first rinsing solution generator and the raw material channel of the second rinsing solution generator are not connected and are respectively supplied with corresponding raw materials.

[0016] The regenerated liquid channel of the first eluent generator is connected to the regenerated liquid channel of the second eluent generator.

[0017] The rinsing solution passes sequentially through the rinsing solution channel of the first rinsing solution generator and the rinsing solution channel of the second rinsing solution generator, and is then used to form the regenerated solution. The regenerated solution then passes sequentially through the regenerated solution channel of the second rinsing solution generator and the regenerated solution channel of the first rinsing solution generator, and is discharged as waste liquid.

[0018] In at least one embodiment, both sides of the rinsing liquid channel of the second rinsing liquid generator are regenerated liquid channels. The rinsing liquid used is converted into regenerated liquid and discharged as waste liquid after passing through the regenerated liquid channels on both sides of the rinsing liquid channel of the second rinsing liquid generator and the regenerated liquid channel of the first rinsing liquid generator.

[0019] In at least one embodiment, the second eluent generator is divided into the eluent channel and the regeneration channel on both sides by two sets of the second ion exchange membranes.

[0020] The chromatographic detection device provided by the embodiments of this application includes the dual-film eluent generator as described above.

[0021] In at least one embodiment, the chromatographic detection device further includes a water source, a pump, an injector, a chromatographic column, a suppressor, and a detector.

[0022] Under the action of the pump, the water supplied by the water source enters the eluent channel to form the eluent. The eluent passes through the injector, the chromatographic column, the suppressor, and the detector before entering the regeneration channel to form the regeneration liquid. Then, after electrolysis, it becomes waste liquid and is discharged from the regeneration channel.

[0023] In at least one embodiment, the chromatographic detection device further includes a stock solution bottle and a stock solution pump, wherein the stock solution circulates between the stock solution bottle and the stock solution channel under the action of the stock solution pump, or

[0024] The stock solution bottle is directly connected to the stock solution channel.

[0025] The dual-film eluent generator provided in this application applies a bipolar membrane between the regeneration channel and the eluent channel of the dual-film eluent generator. This not only enables the eluent channel to receive the corresponding H+ or OH- through electrolytic regeneration, but also prevents impurity ions in the regeneration solution from entering the eluent channel, thereby improving the purity of the eluent.

[0026] The chromatographic detection equipment provided in this application includes the aforementioned dual-membrane eluent generator and also has the aforementioned advantages. Attached Figure Description

[0027] Figure 1 A schematic diagram of a chromatographic detection device including a dual-membrane eluent generator is shown.

[0028] Figure 2 It shows Figure 1 The schematic diagram of the dual-membrane eluent generator.

[0029] Figure 3 , Figure 4 , Figure 5 , Figure 6 Schematic diagrams of four embodiments of a chromatographic detection apparatus including a dual-membrane eluent generator according to embodiments of this application are shown.

[0030] Figure 7 , Figure 8 A schematic diagram of a dual-film eluent generator according to an embodiment of this application is shown.

[0031] Explanation of reference numerals in the attached figures

[0032] 1. First eluent generator; 11. Raw material channel; 12. Eluent channel; 13. Regenerated solution channel;

[0033] 2 Second rinse solution generator; 21 Raw material channel; 22 Rinse solution channel; 23 Regenerated solution channel; 24 Regenerated solution channel;

[0034] 3. First ion exchange membrane group; 31. Ion exchange membrane;

[0035] 4. Second ion exchange membrane assembly; 41. Bipolar membrane;

[0036] 5. Rinse solution generator;

[0037] 61 Cation exchange membrane; 62 Anion exchange membrane; 63 Eluent channel; 64 Stock solution channel; 65 Regenerated solution channel;

[0038] 71 Water source section; 72 Pump; 73 Injector; 74 Chromatographic column; 75 Suppressor; 76 Detector; 77 Stock solution bottle; 78 Stock solution pump. Detailed Implementation

[0039] Exemplary embodiments of this application are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are for teaching those skilled in the art how to implement this application only, and are not intended to exhaustively describe all possible methods of this application, nor to limit the scope of this application.

[0040] A bipolar membrane is a special ion-exchange membrane with a unique ion structure, composed of a cation-anion membrane and an anion-anion membrane, through which neither cations nor anions can pass. However, under the influence of a DC electric field, H₂O between the anion-anion membrane and the cation-anion membrane composite layer in the bipolar membrane dissociates into H⁺ and OH⁻, which can then pass through the cation-anion membrane and enter the corresponding side of the bipolar membrane, respectively. Therefore, applying a bipolar membrane between the regeneration channel and the eluent channel in a dual-membrane eluent generator can both provide the eluent channel with the appropriate H⁺ or OH⁻ through electrolytic regeneration and prevent impurity ions in the regeneration solution from entering the eluent channel.

[0041] This application provides a dual-membrane eluent generator and a chromatographic detection device, which embody the above-mentioned approach.

[0042] The present application provides several embodiments below.

[0043] Example 1

[0044] See Figure 3Example 1 provides a dual-film type eluent generator, which includes a first eluent generator 1. The first eluent generator 1 includes a raw liquid channel 11, an eluent channel 12, and a regenerated liquid channel 13.

[0045] The stock solution in the stock solution channel 11 provides the rinsing solution with the required high concentration of anions or cations, such as potassium ions.

[0046] Water (e.g., pure water) in the eluent channel 12 forms the eluent after passing through the eluent channel 12. A first ion exchange membrane assembly 3 is disposed between the eluent channel 12 and the source solution channel 11. The first ion exchange membrane assembly 3 includes at least one ion exchange membrane 31. The ion exchange membrane 31 is a cation exchange membrane or anion exchange membrane. Cations or anions in the source solution enter the eluent channel 12 through the first ion exchange membrane assembly 3.

[0047] After use, the eluent enters the regeneration channel 13 to become the regeneration solution. A second ion exchange membrane assembly 4 is installed between the eluent channel 12 and the regeneration channel 13. The second ion exchange membrane assembly 4 includes a bipolar membrane 41. Hydrogen ions or hydroxide ions generated after electrolysis of the regeneration solution at the bipolar membrane 41 can enter different sides of the bipolar membrane 41 accordingly. The bipolar membrane 41 can prevent impurity ions other than hydrogen ions or hydroxide ions from entering the eluent channel 12 through the bipolar membrane 41. It can be understood that "used" eluent can refer to its subsequent testing operations through equipment such as injectors, chromatographic columns, and detectors.

[0048] For example, see Figure 7 When the eluent is required to be, for example, KOH, the ion exchange membrane 31 can be a cation exchange membrane, allowing K+ in the raw solution channel 11 to pass through this cation exchange membrane into the eluent channel 12. The bipolar membrane 41 facing the eluent channel 12 is an anion membrane, allowing OH- generated from water electrolysis in the bipolar membrane 41 to pass through its anion membrane into the eluent channel 12, while blocking other impurity ions from entering the eluent channel 12, resulting in higher purity and fewer impurities in the eluent.

[0049] For example, see Figure 8 When the required eluent is, for example, MSA (methanesulfonic acid, chemical formula CH4O3S), the ion exchange membrane 31 can be an anion exchange membrane, and the anions of MSA in the original solution channel 11 ( Figure 8 MSA (representing the anion of MSA) can pass through the anion exchange membrane into the eluent channel 12. The bipolar membrane 41 facing the eluent channel 12 is a cation membrane. H+ generated after water electrolysis in the bipolar membrane 41 can pass through its cation membrane into the eluent channel 12, while blocking other impurity ions from entering the eluent channel 12, thus making the eluent purer.

[0050] It is understood that the aforementioned applications of ion exchange membranes and eluents are merely examples, and this application does not limit the specific types of eluents and ion exchange membranes.

[0051] Further, see Figure 7 , Figure 8 The second ion exchange membrane group 4 may include at least one cation exchange membrane or anion exchange membrane stacked together with the bipolar membrane 41. The first ion exchange membrane group 3 may also be composed of multiple ion exchange membranes 31 stacked together. It is understood that the multilayer membrane stacked structure is beneficial to increasing the mechanical strength and durability of the membrane.

[0052] Further, see Figure 3 One of the positive and negative electrodes is placed in the feed solution channel 11, and the other of the positive or negative electrodes is placed in the regenerated solution channel 13. The positive and negative electrodes can be connected to a constant current power supply. It is understood that this application does not limit the specific positions of the positive and negative electrodes; the electrode positions can be reasonably set according to the feed solution type and the location of each channel. By controlling the current value set by the constant current power supply, the amount of water electrolysis and ion migration can be controlled, thereby controlling the concentration of the eluent.

[0053] See Figure 3 The chromatographic detection equipment provided in this application may include the above-mentioned dual-membrane eluent generator, water source 71, pump 72, injector 73, chromatographic column 74, suppressor 75, detector 76, stock solution bottle 77, and stock solution pump 78.

[0054] Driven by pump 72, water (e.g., pure water) supplied by water source 71 enters eluent channel 12 to form eluent. The eluent passes through injector 73, chromatographic column 74, suppressor 75, detector 76 and enters regeneration channel 13 to form regeneration solution. The regeneration solution is electrolyzed and then discharged.

[0055] Driven by the stock solution pump 78, the stock solution circulates within the stock solution bottle 77 and the stock solution channel 11. This circulation process promotes the flow of air bubbles, preventing bubble aggregation and ensuring the electrolysis process is not affected. Furthermore, compared to designs where both sides of the rinsing liquid channel are stock solution channels, the stock solution channel in this application is relatively short. The stock solution pump 78 only needs to remove air bubbles from one side of the channel, allowing for a lower rotational speed and reduced noise. For example, the stock solution pump 78 can be a peristaltic pump.

[0056] Example 2

[0057] Compared to Figure 3 Example 1 shown, Figure 4The dual-film eluent generator shown in Example 2 remains unchanged. The improvement in Example 2 lies in the connection method between the stock solution bottle and the stock solution channel. Specifically, the stock solution bottle 77 can be directly connected to the stock solution channel 11, and no circulation occurs within the channel. Air bubbles in the stock solution channel 11 can directly enter the stock solution bottle 77 or be discharged through the stock solution bottle 77, thereby reducing the number of pumps required.

[0058] Examples 3 and 4

[0059] See Figure 5 , Figure 6 The dual-film type eluent generator may further include a second eluent generator 2, which includes an eluent channel 22. The eluent channel 12 of the first eluent generator 1 and the eluent channel 22 of the second eluent generator 2 are connected, so that the eluent generated by the first eluent generator 1 can be further adjusted.

[0060] In Example 3, see Figure 5 The second rinsing fluid generator 2 has the same structure as the first rinsing fluid generator 1.

[0061] The raw material channel 11 of the first eluent generator 1 and the raw material channel 21 of the second eluent generator 2 are not connected and are respectively supplied with corresponding raw materials. The types of raw materials can be the same.

[0062] The regenerated liquid channel 13 of the first rinsing liquid generator 1 is connected to the regenerated liquid channel 23 of the second rinsing liquid generator 2. The rinsing liquid passes through the rinsing liquid channel 12 of the first rinsing liquid generator 1 and the rinsing liquid channel 22 of the second rinsing liquid generator 2 in sequence, and is then used to form regenerated liquid. The regenerated liquid then passes through the regenerated liquid channel 23 of the second rinsing liquid generator 2 and the regenerated liquid channel 13 of the first rinsing liquid generator 1 in sequence, and is then discharged as waste liquid.

[0063] In Example 4, see Figure 6 The second rinsing liquid generator 2 has rinsing liquid channels 22 on both sides of the rinsing liquid channel 24. The rinsing liquid used is transformed into regenerated liquid and is discharged as waste liquid after passing through the regenerated liquid channels 24 on both sides of the rinsing liquid channel 22 of the second rinsing liquid generator 2 and the regenerated liquid channel 13 of the first rinsing liquid generator 1.

[0064] The second eluent generator 2 can be divided into an eluent channel 22 and two regeneration channels 24 on both sides by two sets of second ion exchange membrane groups 4.

[0065] In Examples 3 and 4, the second rinsing fluid generator 2 is equivalent to being able to make secondary adjustments to the rinsing fluid. By controlling the type and concentration of its original solution (Example 3), the degree of water electrolysis by the electrode can be controlled, thereby adjusting parameters such as pH and concentration of the rinsing fluid.

[0066] Of course, more applications can be expanded by connecting more rinsing fluid generators and changing the connection method of the rinsing fluid channels and regeneration fluid channels between the rinsing fluid generators.

[0067] The chromatographic detection equipment provided in this application can be liquid chromatography detection equipment, ion chromatography detection equipment, etc.

[0068] The above description is the preferred embodiment of this application. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A dual-membrane type eluent generator, characterized in that, Includes a first eluent generator (1), the first eluent generator (1) comprising: The original solution channel (11) provides the eluent with anions or cations; The rinsing solution channel (12) is formed by water passing through the rinsing solution channel (12). A first ion exchange membrane group (3) is provided between the rinsing solution channel (12) and the original solution channel (11). The first ion exchange membrane group (3) includes at least one ion exchange membrane (31). The ion exchange membrane (31) is a cation exchange membrane or anion exchange membrane. The cations or anions in the original solution enter the rinsing solution channel (12) through the first ion exchange membrane group (3). The regenerated liquid channel (13) is used to enter the regenerated liquid channel (13) to become regenerated liquid. A second ion exchange membrane group (4) is provided between the regenerated liquid channel (12) and the regenerated liquid channel (13). The second ion exchange membrane group (4) includes a bipolar membrane (41). Hydrogen ions or hydroxide ions generated by electrolysis of the regenerated liquid at the bipolar membrane (41) can enter different sides of the bipolar membrane (41). The bipolar membrane (41) can prevent impurity ions other than hydrogen ions or hydroxide ions from entering the regenerated liquid channel (12) through the bipolar membrane (41).

2. The dual-film eluent generator according to claim 1, characterized in that, The second ion exchange membrane assembly (4) also includes at least one cation exchange membrane or anion exchange membrane superimposed on the bipolar membrane (41).

3. The dual-film eluent generator according to claim 1, characterized in that, One of the positive electrode and the negative electrode is placed in the original liquid channel (11), and the other of the positive electrode or the negative electrode is placed in the regenerated liquid channel (13).

4. The dual-film eluent generator according to claim 1, characterized in that, The dual-membrane type eluent generator further includes a second eluent generator (2), which includes an eluent channel (22). The rinsing fluid channel (12) of the first rinsing fluid generator (1) is connected to the rinsing fluid channel (22) of the second rinsing fluid generator (2), so that the rinsing fluid generated by the first rinsing fluid generator (1) can be further adjusted.

5. The dual-film eluent generator according to claim 4, characterized in that, The second eluent generator (2) has the same structure as the first eluent generator (1). The raw liquid channel (11) of the first rinsing liquid generator (1) and the raw liquid channel (21) of the second rinsing liquid generator (2) are not connected and are respectively supplied with corresponding raw liquids. The regenerated liquid channel (13) of the first rinsing liquid generator (1) is connected to the regenerated liquid channel (23) of the second rinsing liquid generator (2). The rinsing fluid passes sequentially through the rinsing fluid channel (12) of the first rinsing fluid generator (1) and the rinsing fluid channel (22) of the second rinsing fluid generator (2) to form the regenerated fluid. The regenerated fluid then passes sequentially through the regenerated fluid channel (23) of the second rinsing fluid generator (2) and the regenerated fluid channel (13) of the first rinsing fluid generator (1) to form waste liquid before being discharged.

6. The dual-film eluent generator according to claim 4, characterized in that, The second rinsing liquid generator (2) has regenerated liquid channels (24) on both sides of the rinsing liquid channel (22). The rinsing liquid used is converted into regenerated liquid and is discharged as waste liquid after passing through the regenerated liquid channels (24) on both sides of the rinsing liquid channel (22) of the second rinsing liquid generator (2) and the regenerated liquid channel (13) of the first rinsing liquid generator (1).

7. The dual-film eluent generator according to claim 6, characterized in that, The second eluent generator (2) is divided into the eluent channel (22) and the regeneration channel (24) on both sides by two sets of the second ion exchange membrane groups (4).

8. A chromatographic detection device, characterized in that, The dual-film eluent generator includes any one of claims 1 to 7.

9. The chromatographic detection device according to claim 8, characterized in that, The chromatographic detection equipment also includes a water source unit (71), a pump (72), an injector (73), a chromatographic column (74), an inhibitor (75), and a detector (76). Under the action of the pump (72), the water supplied by the water source (71) enters the eluent channel (12) to form the eluent. The eluent passes through the injector (73), the chromatographic column (74), the suppressor (75), and the detector (76) before entering the regeneration channel (13) to form the regeneration liquid. Then, after electrolysis, it becomes waste liquid and is discharged from the regeneration channel (13).

10. The chromatographic detection apparatus according to claim 8, characterized in that, The chromatographic detection device also includes a stock solution bottle and a stock solution pump. Under the action of the stock solution pump, the stock solution circulates between the stock solution bottle and the stock solution channel (11), or The stock solution bottle is directly connected to the stock solution channel (11).

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