Novel configuration of an ultrahigh pressure electrolytic eluent generator

Abstract

An electrolytic eluent generator includes an electrolyte reservoir and at least one eluent generation cartridge. The electrolyte reservoir includes a chamber containing an aqueous electrolyte solution and a first electrode. The at least one eluent generation cartridge includes a platinum mesh electrode, a polymeric screen, a plurality of reinforced membranes, a membrane gasket, and a spacer including a central post and an annular protrusion.

Description

Technical Field

[0001] This disclosure generally relates to the field of ion chromatography, including ultra-high pressure electrolytic eluent generators (EEG). Background Technology

[0002] Ion chromatography (IC) is a well-established analytical technique that has been the preferred method for determining inorganic and small organic anions for the past 40 years. IC is also widely used for determining inorganic cations, as well as carbohydrates and amino acids.

[0003] In ion chromatography, dilute solutions of acids, bases, or salts are commonly used as eluents for chromatographic separation. Traditionally, these eluents are prepared offline by dilution with reagent-grade chemicals. Offline preparation of chromatographic eluents can be tedious and prone to operator error, and often introduces contaminants. For example, dilute NaOH solutions, widely used as eluents in anion ion chromatography, are susceptible to carbonate contamination. The preparation of carbonate-free NaOH eluents is challenging because carbonates can be introduced as impurities from the reagent or by absorbing carbon dioxide from the air. The presence of carbonates in NaOH eluents can impair the performance of ion chromatography methods and may cause undesirable baseline drift during hydroxide gradients and even during irreproducible retention times of the target analyte. In recent years, researchers have investigated several methods utilizing water electrolysis and charge-selective electromigration of ions through ion-exchange media to purify or generate high-purity ion chromatography eluents. U.S. Patents 6,036,921, 6,225,129, 6,316,271, 6,316,270, 6,315,954, and 6,682,701 describe electrolytic devices that can be used to generate high-purity acid and base solutions by using water as a carrier. Using these devices, high-purity, uncontaminated acid or base solutions can be automatically generated online for use as eluents in chromatographic separations.

[0004] The introduction of electrolytic devices for online generation of pure eluents ushered in a new era for ion chromatography. Its growth has been rapid due to the superiority of EEG over traditional manual preparation methods (e.g., high-purity eluents, excellent concentration reproducibility achieved through precise control of constant current, ease of use, etc.). Electrolyzed eluents are now widely used in many fields, including environmental protection, biotechnology, pharmaceuticals, power plants, and the food industry.

[0005] As ion chromatography has advanced in the field of ultra-high performance liquid chromatography (UHPLC) to use separation columns with smaller diameters and smaller bead sizes, the operating pressure required for EEG has increased. Therefore, there is a need for improved EEG. Summary of the Invention

[0006] In the first aspect, the eluent generation box may include a platinum mesh electrode; a polymer sieve; multiple reinforced membranes; membrane gaskets; and spacers including a central column and annular protrusions.

[0007] In various embodiments of the first aspect, the eluent generation cartridge may be configured to operate at a pressure of at least about 5,000 psi, such as at least about 10,000 psi. In a particular embodiment, the eluent generation cartridge may be configured to operate at a pressure of no more than about 30,000 psi, such as no more than about 15,000 psi.

[0008] In various embodiments of the first aspect, the plurality of enhanced membranes comprise at least about 5 ion exchange membranes, such as no more than about 100 ion exchange membranes.

[0009] In various embodiments of the first aspect, the membrane gasket comprises at least one ion exchange membrane, such as no more than about 20 ion exchange membranes.

[0010] In a second aspect, the electrolytic eluent generator may include an electrolyte reservoir and at least one eluent generation box. The electrolyte reservoir may include: a chamber containing an aqueous electrolyte solution; and a first electrode. The at least one eluent generation box may include a platinum mesh electrode; a polymer sieve; multiple reinforced membranes; membrane gaskets; and a spacer including a central pillar and an annular protrusion.

[0011] In various embodiments of the second aspect, the eluent generation cartridge may be configured to operate at a pressure of at least about 5,000 psi, such as at least about 10,000 psi. In a particular embodiment, the eluent generation cartridge may be configured to operate at a pressure of no more than about 30,000 psi, such as no more than about 15,000 psi.

[0012] In various embodiments of the second aspect, the aqueous electrolyte solution contains potassium hydroxide or sodium hydroxide.

[0013] In various embodiments of the second aspect, the aqueous electrolyte solution contains methanesulfonic acid.

[0014] In various embodiments of the second aspect, the plurality of enhanced membranes comprise at least about 5 ion exchange membranes, such as no more than about 100 ion exchange membranes.

[0015] In various embodiments of the second aspect, the membrane gasket comprises at least one ion exchange membrane, such as no more than about 20 ion exchange membranes. Attached Figure Description

[0016] To more fully understand the principles and advantages disclosed herein, the following description is now provided with reference to the accompanying drawings, in which:

[0017] Figure 1 Chromatographic systems including an eluent generator are shown according to various embodiments.

[0018] Figure 2 An eluent generator according to various embodiments is shown.

[0019] Figure 3A and 3B Eluent generation kits according to various embodiments are shown.

[0020] Figure 4A and 4B An improved eluent generation kit according to various embodiments is shown.

[0021] It should be understood that the drawings are not necessarily drawn to scale, nor are the relationships between objects in the drawings necessarily drawn to scale. The drawings are intended to provide clear and easy-to-understand depictions of the various embodiments of the devices, systems, and methods disclosed herein. Where appropriate, the same reference numerals will be used throughout the drawings to refer to the same or similar parts. Furthermore, it should be understood that the drawings are not intended to limit the scope of this teaching in any way. Detailed Implementation

[0022] This article describes an example of ultra-high voltage EEG.

[0023] The chapter titles used in this article are for organizational purposes only and should not be construed as limiting the subject matter in any way.

[0024] In this detailed description of various embodiments, numerous specific details are set forth for illustrative purposes to provide a thorough understanding of the disclosed embodiments. However, those skilled in the art will appreciate that these various embodiments may be practiced with or without these specific details. In other instances, structures and apparatus are shown in block diagram form. Furthermore, those skilled in the art will readily understand that the particular order in which the methods are presented and performed is illustrative and that the order may be altered while still remaining within the spirit and scope of the various embodiments disclosed herein.

[0025] All documents and similar materials cited in this application, including but not limited to patents, patent applications, papers, books, monographs, and Internet web pages, are expressly incorporated herein by reference in their entirety for any purpose. Unless otherwise described, all technical and scientific terms used herein have the meanings commonly understood by one of ordinary skill in the art to which the various embodiments described herein pertain.

[0026] It should be understood that the terms "about" are implicitly used before terms such as temperature, concentration, time, pressure, flow rate, and cross-sectional area discussed in the teachings of this invention, resulting in slight and non-material deviations within the scope of the teachings. In this application, unless otherwise specifically stated, the use of the singular includes the plural. Furthermore, the use of "comprise," "contain," and "include" is not intended to be restrictive. It should be understood that the foregoing general description and the following detailed description are merely exemplary and illustrative, and do not limit the teachings of this invention.

[0027] As used herein, “a / an” can also mean “at least one” or “one or more”. Furthermore, the use of “or” is inclusive, such that the phrase “A or B” is true when “A” is true, “B” is true, or both “A” and “B” are true. Additionally, unless the context otherwise requires, singular terms should include plural terms and plural terms should include singular terms.

[0028] A “system” describes a set of real or abstract components, including the whole, in which each component interacts with or is related to at least one other component within the whole.

[0029] Chromatography system

[0030] Figure 1 An embodiment of a chromatography system is illustrated. The chromatography system may include a pump 102, an electrolytic eluent generator 104, a continuously regenerating capture column 106, a degasser 108, a sample injector 110, a chromatographic separation column 112, an electrolytic suppressor 114, a detector 116, and a microprocessor 118. The chromatographic separation column 112 may be in the form of a capillary column or an analytical column. A recirculation line 120 may be used to transfer liquid from the output of the detector 116 to the inlet of the electrolytic suppressor 114, a recirculation line 122 may be used to transfer liquid from the outlet of the electrolytic suppressor 114 to the inlet of the degasser 108, and a recirculation line 124 may be used to transfer liquid from the outlet of the degasser 108 to the inlet of the continuously regenerating capture column 106.

[0031] Pump 102 can be configured to pump liquid from liquid source 124 and fluidly connect to electrolytic eluent generator 104. In one embodiment, the liquid can be deionized water, an aqueous solution having one or more electrolytes, or a mixture of an organic solvent with deionized water or with one or more aqueous electrolyte solutions. Several examples of electrolytes are sodium acetate and acetic acid. Eluent mixtures containing organic solvents can contain water-miscible organic solvents, such as methanol. Pump 102 can be configured to deliver the liquid at a pressure ranging from about 20 PSI to about 15,000 PSI. In some cases, pressures greater than 15,000 PSI can also be implemented. It should be noted that the pressures indicated herein are listed relative to ambient pressure (13.7 PSI to 15.2 PSI). Pump 102 can take the form of a high-performance liquid chromatography (HPLC) pump. Additionally, pump 102 can also be configured such that the liquid only contacts the inert portion of pump 102, thereby preventing the filtration of significant amounts of impurities. In this context, "significant" means the amount of impurities that would interfere with the expected measurement results. For example, the inert portion can be made of polyetheretherketone (PEEK), or at least coated with a PEEK lining that does not leach large amounts of ions when exposed to liquids.

[0032] The eluent is a liquid containing an acid, base, salt, or a mixture thereof, and can be used to elute analytes through a chromatographic column. Alternatively, the eluent may contain a mixture of a liquid and a water-miscible organic solvent, wherein the liquid may contain an acid, base, salt, or a combination thereof. The electrolytic eluent generator 104 is configured to generate a product. The product refers to an acid, base, or salt of a specific species that can be added to the eluent. In one embodiment, the product may be a base, such as a cationic hydroxide, or the product may be an acid, such as carbonic acid, phosphoric acid, acetic acid, methanesulfonic acid, or a combination thereof.

[0033] Reference Figure 1 The eluent generator 104 can be configured to receive liquid from the pump 102 and then add the product to the liquid. The liquid containing the product can be output from the eluent generator 104 to the inlet of the continuous regeneration capture column 106.

[0034] The continuously regenerating capture column 106 is configured to remove cationic or anionic contaminants from the eluent. The continuously regenerating capture column 106 may comprise an ion exchange bed with electrodes at the eluent outlet. An ion exchange membrane interface separates the eluent from a second electrode, and contaminant ions can be swept through the ion exchange membrane toward the second electrode. In various embodiments, anion removal may utilize an anion exchange bed, wherein the cathode at the eluent outlet is separated from the anode by an anion exchange membrane. Alternatively, cation removal may utilize a cation exchange bed, wherein the anode at the eluent outlet is separated from the cathode by a cation exchange membrane. Contaminant ions can be filtered from the regenerated capture column 106 using recirculated liquid through a recirculation line 124 located downstream of the degasser assembly 108.

[0035] Degasser 108 can be used to remove residual gases from the eluent. In one embodiment, the residual gases may be hydrogen and oxygen. Degasser 108 may include gas-permeable and liquid-impermeable piping sections, such as amorphous fluoropolymers or more specifically Teflon AF. Flowing liquid can be output from degasser 108 to sample injector 110, where a significant portion of the gas has been removed. Gas can be filtered out of degasser 108 using recirculated liquid through recirculation line 122 downstream of electrolysis suppressor 114. Recirculated liquid containing residual gas can also be output from degasser 108 and directed into continuous regeneration capture column 106.

[0036] The sample injector 110 can be used to inject large volumes of liquid sample into the eluent stream. The liquid sample may contain multiple chemical components (i.e., matrix components) and one or more analytes of interest.

[0037] The chromatographic column 112 can be used to separate various matrix components present in a liquid sample from the analyte of interest. Typically, the chromatographic column 112 can be in the form of a hollow cylinder containing a packed stationary phase. When the liquid sample flows through the chromatographic column 112, the matrix components and the target analyte can have specific retention time ranges for elution from the column 112. Depending on the characteristics of the target analyte and the matrix components, they can have different affinities for the stationary phase in the chromatographic column 112. The output of the chromatographic column 112 can be fluidly connected to an electrolytic suppressor 114.

[0038] Electrolysis suppressor 114 can be used to reduce eluent conductivity background and enhance analyte response by effectively exchanging eluent counterions for regenerator ions. Electrolysis suppressor 114 may include an anode chamber, a cathode chamber, and an eluent suppression bed chamber separated by an ion exchange membrane. The anode chamber and / or cathode chamber can generate regenerator ions. The eluent suppression bed chamber may include a flow path for the eluent separated from the regenerator across the ion exchange barrier, and the eluent counterions can exchange with the regenerator ions across the ion exchange barrier. The cathode chamber or anode chamber can be supplied with recirculated liquid via a recirculation line 120 located downstream of conductivity detector 116. The output of electrolysis suppressor 114 can be fluidly connected to detector 116 to measure the presence of separated chemical components in a liquid sample.

[0039] like Figure 1 As shown, the fluid output of the eluent from detector 116 is recirculated to electrolysis suppressor 114 via recirculation line 120, the fluid output of electrolysis suppressor 114 is recirculated to degasser 108 via recirculation line 122, the fluid output of degasser 108 is recirculated to continuous regeneration capture column 106 via recirculation line 124, and the fluid output of continuous regeneration capture column 106 flows to waste.

[0040] Detector 116 may take the form of a UV-Vis spectrometer, a fluorescence spectrometer, an electrochemical detector, a conductivity detector, a charge detector, or a combination thereof. Details regarding charge detectors based on charged barriers and two electrodes can be found in U.S. Pre-Publication Publication No. 20090218238, which is incorporated herein by reference in its entirety. Where the recirculation line 120 is not required, detector 116 may also take the form of a mass spectrometer or a charge sol detector. The charge sol detector sprays an effluent flow and generates charged particles, which can be measured as a current proportional to the analyte concentration. Details regarding charge sol detectors can be found in U.S. Patents 6,544,484 and 6,568,245, which are incorporated herein by reference in their entirety.

[0041] The electronic circuitry may include a microprocessor 118, a timer, and a memory section. Additionally, the electronic circuitry may include power supplies configured to apply control signals. The microprocessor 118 can be used to control the operation of the chromatography system. The microprocessor 118 may be integrated into the chromatography system or as part of a personal computer that communicates with the chromatography system. The microprocessor 118 may be configured to communicate with and control one or more components of the chromatography system, such as pump 102, eluent generator 104, sample injector 110, and detector 116. The memory section may be used to store instructions to set the magnitude and timing of the current waveform relative to the switching of the sample injector 110 with respect to the injected sample.

[0042] Figure 2 The operating principle of an electrolytic eluent generator cartridge 200 is illustrated. The cartridge may include a high-pressure eluent generation chamber 202 and a low-pressure electrolyte reservoir 204. In various embodiments, the high-pressure generation chamber 202 can operate at pressures greater than about 2,000 psi, such as at least about 5,000 psi, or even at least about 10,000 psi, but not greater than about 30,000 psi, such as not greater than about 15,000 psi.

[0043] The eluent generation chamber 202 may contain a porous platinum (Pt) electrode 206. The electrolyte reservoir 204 may contain a Pt electrode 208 and an electrolyte solution. In various embodiments, the electrolytic eluent generator box 200 may generate a base, such as KOH, where electrode 206 may be a cathode capable of forming hydroxide ions, and electrode 208 may be an anode. In other embodiments, the electrolytic eluent generator box 200 may generate an acid, such as carbonic acid, phosphoric acid, acetic acid, or methanesulfonic acid, where electrode 206 may be an anode capable of forming hydrogen ions, and electrode 208 may be a cathode. The eluent generation chamber 202 may be connected to the electrolyte reservoir 204 via an exchange connector 210, which allows ions of only one charge to enter the high-voltage generation chamber 202 from the electrolyte reservoir 204. The exchange connector 210 also serves as a critical high-voltage physical barrier between the low-voltage electrolyte reservoir 204 and the high-voltage generation chamber 202. In various embodiments where the electrolytic eluent generator cartridge 200 is an alkali generator, the exchange connector 210 allows the transfer of anions while substantially preventing the transfer of anions from the electrolyte reservoir 204 to the generation chamber 202. In alternative embodiments where the electrolytic eluent generator cartridge 200 is an acid generator, the exchange connector 210 allows the transfer of anions while substantially preventing the transfer of cations from the electrolyte reservoir 204 to the generation chamber 202.

[0044] In various embodiments, the eluent generation chamber 202 and the ion exchange connector 210 can be assembled into the eluent generation box.

[0045] To generate KOH eluent, deionized water can be pumped through the eluent generation chamber 202, and a DC current can be applied between electrodes 208 and 206. Under the applied electric field, water electrolysis can occur at both electrodes 208 and 206 of the device 200. Water can be oxidized at electrode 208 in the electrolyte reservoir 204 to form H+ ions and oxygen gas: H2O → 2H+ + 1 / 2O2↑ + 2e-. Water can be reduced at electrode 206 in the KOH generation chamber 202 to form OH- ions and hydrogen gas: 2H2O + 2e- → 2OH- + H2↑. When the H+ ions generated at anode 206 replace the K+ ions in the electrolyte reservoir 204... + During ionization, the replaced ions can migrate across the cation exchange connector 210 into the eluent generation chamber 202. These K... + Ions can combine with hydroxide ions generated at cathode 206 to produce a KOH solution, which can be used as an eluent for anion exchange chromatography. The concentration of generated KOH can be determined by the current applied to generator cartridge 200 and the flow rate of carrier water through generation chamber 202.

[0046] To generate methanesulfonic acid eluent, deionized water can be pumped through the eluent generation chamber 202, and a DC current can be applied between electrodes 208 and 206. Under the applied current, water electrolysis can occur at both electrodes 208 and 206 of the device 200. Water can be oxidized at electrode 206 in the KOH generation chamber 202 to form H+ ions and oxygen gas: H2O → 2H+ + 1 / 2O2↑ + 2e-. Water can be reduced at electrode 208 in the electrolyte reservoir 204 to form OH- ions and hydrogen gas: 2H2O + 2e- → 2OH- + H2↑. When OH- ions are generated at electrode 206... - When methanesulfonate ions are ion-displaced in the electrolyte reservoir 204, the displaced ions can migrate across the anion exchange connector 210 into the eluent generation chamber 202. These methanesulfonate ions can combine with hydrated hydrogen ions generated at electrode 206 to produce a methanesulfonic acid solution, which can be used as an eluent for cation exchange chromatography. The concentration of the generated methanesulfonic acid can be determined by the current applied to the generator cartridge 200 and the flow rate of the carrier water through the generation chamber 202.

[0047] Stacked ion exchange membranes are the core of an electrolytic eluent generator. The physical and chemical properties of the membranes are crucial to the quality and performance of the electrolytic eluent generator in order to generate pure eluent for ion chromatography in-line. In addition to these two factors, another key factor is the continuity of the stacked membranes, which determines the operating voltage when a constant current is applied to the electrolytic eluent generator. Membrane continuity issues can arise during EGC assembly and operation, leading to low production yields and unsatisfactory performance due to overvoltage problems. This paper discloses a novel configuration consisting of a top membrane gasket and a disc containing spacers to address the challenge of high torque forces encountered during assembly and application under high-pressure conditions. This novel configuration can be used to overcome overvoltage problems during cartridge assembly in applications with high torque forces. Furthermore, this configuration can be used for the successful assembly of EGC KOH and MSA cartridges, enabling these cartridges to be electrolyzed at ultra-high pressure to generate pure eluent.

[0048] Figure 3A and 3B An eluent generation cartridge 300 is shown. The eluent generation cartridge 300 may include a platinum mesh electrode 302, a polymer sieve 304, multiple ion exchange membrane stacks 306, 308, and 310, and a spacer 312. The spacer 312 includes an annular protrusion 314 that forms a seal with the ion exchange membrane 310 while allowing the electrolyte solution to contact the ion exchange membrane 310 within a space 316 inside the annular protrusion 314.

[0049] Multiple ion exchange membranes 306, 308, and 310 are compressed by spacer 312. A torque force is applied to a compression bolt (not shown). The compressive force is then transmitted through spacer 312 to the ion exchange membranes 306, 308, and 310, and spacer 312, having an annular protrusion 314 near its periphery, is pushed downwards to create a seal. The compression of membranes 306, 308, and 310 by the annular protrusion 314 causes membrane deformation, such as… Figure 3B As shown, deformation varies from the periphery to the center. The membrane deformation is greatest near the center, causing the entire membrane 310 to expand into space 316, thus creating a void 318 between membranes 308 and 310. For moderate torque forces, membrane deformation can be small, and its impact on the continuity of the stacked membranes during assembly and operation is negligible. However, when ultra-high pressure EEG cells require high torque forces, membrane discontinuities during the torque process can become a problem. Voids formed during ultra-high pressure compression can lead to electrical discontinuities, resulting in voltage spikes and increased resistance.

[0050] Figure 4A and 4BAn eluent generation cartridge 400 is shown. The eluent generation cartridge 400 may include a platinum mesh electrode 402, a polymer sieve 404, multiple ion exchange membrane stacks 406 and 408, membrane gaskets 410, and spacers 412. Spacers 412 include annular protrusions 414 and a central pillar 416 similar to spacer 312. Electrolyte solution can contact the membrane stacks 408 and membrane gaskets 410 in an annular space 418 between the annular protrusions 414 and the central pillar 416.

[0051] In various embodiments, the plurality of ion exchange membrane stacks 406 and 408 may comprise a plurality of ion exchange membranes, at least a portion of which may be enhanced membranes. In various embodiments, the total number of ion exchange membranes (including enhanced and non-enhanced ion exchange membranes) may be at least about five ion exchange membranes. Typically, the ion exchange membrane stacks 406 and 408 together may comprise no more than about 100 ion exchange membranes.

[0052] In various embodiments, the membrane gasket 410 may comprise one or more ion exchange membranes. Typically, the membrane gasket 410 may comprise no more than about 20 ion exchange membranes.

[0053] like Figure 4B As shown, during compression, the membrane gasket 410 can deform into the annular space 418, thereby forming a gap 420 between the membrane gasket 410 and the ion exchange membrane 408. However, the electrolyte solution 422 can flow into the gap 420, preventing... Figure 3A and 3B The discontinuity in the illustrated embodiment.

[0054] While the teachings of the invention have been described in conjunction with various embodiments, the teachings are not intended to be limited to such embodiments. Rather, the teachings encompass various alternatives, modifications, and equivalents, as will be appreciated by those skilled in the art.

[0055] Furthermore, in describing various embodiments, this specification may present methods and / or processes as steps in a specific order. However, methods or processes should not be limited to the specific order of steps described herein, to the extent that they do not depend on such a specific order. As will be appreciated by those skilled in the art, other orders of steps may be possible. Therefore, the specific order of steps set forth in this specification should not be construed as a limitation of the claims. Additionally, the claims for the methods and / or processes should not be limited to performing the steps in the written order, and those skilled in the art will readily understand that the sequence can be altered while still remaining within the spirit and scope of the various embodiments.

Claims

1. An eluent generation kit (400), comprising: Platinum mesh electrode (402); Polymer sieve (404); Multiple ion exchange membrane stacks (406, 408), including multiple enhanced ion exchange membranes; Membrane gasket (410), comprising at least one ion exchange membrane; and A spacer (412) comprising a central post (416) and an annular protrusion (414), wherein during compression, the membrane gasket (410) can deform into the annular space (418) between the annular protrusion (414) and the central post (416), thereby forming a gap (420) between the membrane gasket (410) and the ion exchange membrane (408).

2. The eluent generation cartridge (400) according to claim 1, wherein the eluent generation cartridge (400) is configured to operate at a pressure of at least 5,000 psi.

3. The eluent generation cartridge (400) according to claim 2, wherein the eluent generation cartridge (400) is configured to operate at a pressure of at least 10,000 psi.

4. The eluent generation cartridge (400) according to claim 2, wherein the eluent generation cartridge (400) is configured to operate at a pressure not exceeding 30,000 psi.

5. The eluent generation cartridge (400) according to claim 4, wherein the eluent generation cartridge (400) is configured to operate at a pressure not exceeding 15,000 psi.

6. The eluent generation box (400) according to claim 1, wherein the plurality of ion exchange membrane stacks (406, 408) comprises at least 5 enhanced ion exchange membranes.

7. The eluent generation box (400) according to claim 6, wherein the plurality of ion exchange membrane stacks (406, 408) comprises no more than 100 enhanced ion exchange membranes.

8. The eluent generation box (400) according to claim 1, wherein the membrane gasket (410) comprises no more than 20 ion exchange membranes.

9. An electrolytic eluent generator, comprising: Electrolyte reservoir, the electrolyte reservoir comprising: A chamber containing an aqueous electrolyte solution; and First electrode; At least one eluent generation cartridge (400), the eluent generation cartridge (400) comprising: Platinum mesh electrode (402); Polymer sieve (404); Multiple ion exchange membrane stacks (406, 408) containing multiple enhanced ion exchange membranes; Membrane gasket (410), comprising at least one ion exchange membrane; and A spacer (412) comprising a central post (416) and an annular protrusion (414), wherein during compression, the membrane gasket (410) can deform into the annular space (418) between the annular protrusion (414) and the central post (416), thereby forming a gap (420) between the membrane gasket (410) and the ion exchange membrane (408).

10. The electrolytic eluent generator of claim 9, wherein the eluent generation cartridge (400) is configured to operate at a pressure of at least 5,000 psi.

11. The electrolytic eluent generator of claim 10, wherein the eluent generation cartridge (400) is configured to operate at a pressure of at least 10,000 psi.

12. The electrolytic eluent generator of claim 10, wherein the eluent generation cartridge (400) is configured to operate at a pressure not exceeding 30,000 psi.

13. The electrolytic eluent generator of claim 12, wherein the eluent generation cartridge (400) is configured to operate at a pressure not exceeding 15,000 psi.

14. The electrolytic eluent generator according to claim 9, wherein the aqueous electrolyte solution comprises potassium hydroxide or sodium hydroxide.

15. The electrolytic eluent generator according to claim 9, wherein the aqueous electrolyte solution comprises methanesulfonic acid.

16. The electrolytic eluent generator according to claim 9, wherein the plurality of ion exchange membrane stacks (406, 408) comprises at least 5 enhanced ion exchange membranes.

17. The electrolytic eluent generator of claim 16, wherein the plurality of ion exchange membrane stacks (406, 408) comprises no more than 100 enhanced ion exchange membranes.

18. The electrolytic eluent generator according to claim 9, wherein the membrane gasket (410) comprises no more than 20 ion exchange membranes.

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