Gasless Eluent Generator

Abstract

The eluent generation module includes an electrolytic gas generator and an electrolytic eluent generator. The electrolytic gas generator includes a production chamber having an inlet and an outlet, an outlet electrode within the production chamber, a first ion exchange connector, a bulk solvent chamber separated from the production chamber by the ion exchange connector, and a bulk solvent chamber electrode within the bulk solvent chamber. The electrolytic eluent generator includes an electrolyte chamber containing an aqueous electrolyte solution, an electrolyte chamber electrode within the electrolyte chamber, a second ion exchange connector, an eluent generation chamber separated from the electrolyte chamber by the second ion exchange connector, and an eluent generation chamber electrode.

Description

[Technical Field]

[0001] The present disclosure relates generally to the field of ion chromatography, including gasless eluent generators. Introduction

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

[0003] In ion chromatography, dilute solutions of acids, bases, or salts are commonly used as chromatographic separation eluents. Traditionally, these eluents are prepared offline by dilution with reagent-grade chemicals. Offline preparation of chromatographic eluents is tedious, prone to operator error, and often leads to contamination. For example, dilute NaOH solutions, which are widely used as eluents in ion chromatographic separations of anions, are easily contaminated with carbonates. Preparing carbonate-free NaOH eluents is difficult because carbonates can be introduced as impurities from reagents or by adsorption of carbon dioxide from the air. The presence of carbonates in NaOH eluents can impair the performance of ion chromatography methods and can also cause undesirable chromatographic baseline shifts during hydroxide gradients, leading to irreproducible retention times of target analytes. In recent years, researchers have investigated several approaches utilizing the electrolysis of water and charge-selective electromigration of ions through ion exchange media to purify or produce high-purity ion chromatography eluents. U.S. Patent Nos. 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 produce high-purity acid and base solutions using water as a carrier. Using these devices, high-purity, contaminant-free acid or base solutions are automatically produced in-line for use as eluents in chromatographic separations.

[0004] The introduction of electrolytic devices for the online generation of pure eluents has propelled ion chromatography into a new era. Since then, ion chromatography has grown rapidly due to the advantages that the use of electrolytic eluent generators (EEGs) offers over traditional manual preparation methods, including high-purity eluents, excellent concentration reproducibility due to precise control of constant current, and ease of use. Electrolytically generated eluents are widely used in many application areas, including environmental protection, biotechnology, the pharmaceutical industry, power plants, and the food industry.

[0005] However, electrolytic devices often deliver dissolved gases into the eluent as a by-product of electrolysis. Before using the eluent in ion chromatography, it may be necessary to remove the dissolved gases, such as with a degasser. Therefore, improved EEG is needed. Summary of the Invention

[0006] In a first aspect, the eluent generation module can include an electrolytic gas generator and an electrolytic eluent generator. The electrolytic gas generator can include a production chamber having an inlet and an outlet, an outlet electrode within the production chamber, a first ion exchange connector, a bulk solvent chamber separated from the production chamber by the ion exchange connector, and a bulk solvent chamber electrode within the bulk solvent chamber. The electrolytic eluent generator can include an electrolyte chamber containing an aqueous electrolyte solution, an electrolyte chamber electrode within the electrolyte chamber, a second ion exchange connector, an eluent generation chamber separated from the electrolyte chamber by the second ion exchange connector, and an eluent generation chamber electrode.

[0007] In various embodiments of the first aspect, the electrolytic eluent generator can be configured to generate an acid eluent, the second ion exchange connector can include an anion exchange barrier, the electrolyte chamber electrode can be a cathode, and the eluent generation chamber electrode can be an anode. In embodiments, the electrolytic gas generator can be configured to generate H2 at the outlet and combine with the O2 generated at the eluent generation chamber electrode, the first ion exchange connector can include an anion exchange barrier, the outlet electrode can be a cathode, and the bulk solvent chamber electrode can be an anode. The aqueous electrolyte solution can include carbonic acid, sulfuric acid, phosphoric acid, acetic acid, methanesulfonic acid, or any combination thereof. In certain embodiments, the generation chamber can include an anion ion exchange bed.

[0008] In various embodiments of the first aspect, the eluent generation module can be configured to generate a base eluent, the second ion exchange connector can include a cation exchange barrier, the electrolyte chamber electrode can be the anode, and the eluent generation chamber electrode can be the cathode. In embodiments, the electrolytic gas generator can be configured to generate O2 at the outlet and combine with the H2 generated at the eluent generation chamber electrode, the first ion exchange connector can include a cation exchange barrier, the outlet electrode can be the anode, and the bulk solvent chamber electrode can be the cathode. The aqueous electrolyte solution can include potassium hydroxide, sodium hydroxide, lithium hydroxide, other alkali hydroxides, or any combination thereof. In certain embodiments, the generation chamber can include a cation exchange bed.

[0009] In various embodiments of the first aspect, the exit electrode may be a perforated platinum electrode.

[0010] In a second aspect, a method for producing a gas-free base eluent can include supplying a liquid to an inlet of an electrolytic gas generator. The electrolytic gas generator can include a production chamber having an inlet and an outlet, an outlet anode within the production chamber, a first cation exchange connector, a bulk solvent chamber separated from the production chamber by the cation exchange connector, and a bulk solvent chamber cathode within the bulk solvent chamber. The method can further include applying a current across the outlet anode and the bulk solvent chamber cathode to produce O at the outlet anode, and providing a liquid stream containing oxygen gas from the outlet to the electrolytic eluent generator. The electrolytic eluent generator can include an electrolyte chamber containing an aqueous electrolyte solution, an electrolyte chamber anode within the electrolyte chamber, a second cation exchange connector, an eluent production chamber separated from the electrolyte chamber by the second cation exchange connector, and an eluent production chamber cathode. The method may further include applying a current across the electrolyte chamber anode and the eluent generation chamber cathode to migrate electrolyte ions from the electrolyte chamber across a second cation exchange connector to form a base eluent in the eluent generation chamber, and reacting O with the H formed at the eluent generation chamber cathode to produce a gas-free base eluent.

[0011] In various embodiments of the second aspect, the aqueous electrolyte solution can include potassium hydroxide, sodium hydroxide, lithium hydroxide, other alkali hydroxides, or any combination thereof.

[0012] In various embodiments of the second aspect, the exit anode can be a perforated platinum anode.

[0013] In various embodiments of the second aspect, the gas-free base eluent may contain less than about 0.2 mL of gas per mL of eluent, such as less than about 0.1 mL of gas per mL of eluent, or even less than about 0.05 mL of gas per mL of eluent.

[0014] In various embodiments, the second aspect may further include injecting a sample onto a chromatography column; varying a current applied across the production chamber anode and the bulk solvent chamber cathode of the electrolytic gas generator; varying a current applied across the electrolyte chamber anode and the eluent production chamber cathode to vary the concentration of the gas-free base eluent; supplying the gas-free base eluent to the chromatography column; eluting the sample analytes from the chromatography column; and detecting the sample analytes using a detector.

[0015] In a third aspect, a method for producing a gas-free acid eluent can include supplying a liquid to an inlet of an electrolytic gas generator. The electrolytic gas generator can include a production chamber having an inlet and an outlet, an outlet cathode within the production chamber, a first anion exchange connector, a bulk solvent chamber separated from the production chamber by the anion exchange connector, and a bulk solvent chamber anode within the bulk solvent chamber. The method can further include applying a current across the outlet cathode and the bulk solvent chamber anode to produce H at the outlet cathode and providing a liquid stream containing hydrogen gas from the outlet to the electrolytic eluent generator. The electrolytic eluent generator can include an electrolyte chamber containing an aqueous electrolyte solution, an electrolyte chamber cathode within the electrolyte chamber, a second anion exchange connector, an eluent production chamber separated from the electrolyte chamber by the second anion exchange connector, and an eluent production chamber anode. The method may further include applying a current across the electrolyte chamber cathode and the eluent generation chamber anode to migrate electrolyte ions from the electrolyte chamber across a second anion exchange connector to form an acid eluent in the eluent generation chamber, and reacting H with the O formed at the eluent generation chamber anode to produce a gas-free acid eluent.

[0016] In various embodiments of the third aspect, the aqueous electrolyte solution can include carbonic acid, sulfuric acid, phosphoric acid, acetic acid, methanesulfonic acid, or any combination thereof.

[0017] In various embodiments of the third aspect, the exit electrode may be a perforated platinum electrode.

[0018] In various embodiments of the third aspect, the gas-free acid eluent may contain less than about 0.2 mL of gas per mL of eluent, such as less than about 0.1 mL of gas per mL of eluent, or even less than about 0.05 mL of gas per mL of eluent.

[0019] In various embodiments, the third aspect may further include injecting a sample onto a chromatography column; varying a current applied across the production chamber cathode and the bulk solvent chamber anode of the electrolytic gas generator and varying a current applied across the electrolyte chamber cathode and the eluent production chamber anode to vary the concentration of the gas-free acid eluent; supplying the gas-free acid eluent to the chromatography column; eluting the sample analytes from the chromatography column; and detecting the sample analytes using a detector.

[0020] For a more complete understanding of the principles disclosed herein, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0021] [Figure 1] 1 illustrates a chromatography system including an eluent generation module, according to various embodiments. [Figure 2] 1 illustrates an eluent generation module, according to various embodiments. [Figure 3A] 1 illustrates an electrolytic gas generator, according to various embodiments. [Figure 3B] 1 illustrates an electrolytic gas generator, according to various embodiments. [Figure 4] FIG. 1 is a flow diagram illustrating a method for using a chromatography system including an eluent generation module, according to various embodiments. [Figure 5]FIG. 1 is a flow diagram illustrating a method for using a chromatography system including an eluent generation module, according to various embodiments.

[0022] It should be understood that the figures are not necessarily drawn to scale, and that objects within the figures are not necessarily drawn to scale in relationship to each other. The figures are representations intended to provide clarity and understanding of various embodiments of the devices, systems, and methods disclosed herein. Wherever possible, the same reference numbers will be used throughout the figures to refer to the same or like parts. Furthermore, it should be understood that the figures are not intended to limit the scope of the present teachings in any way. DETAILED DESCRIPTION OF THE INVENTION

[0023] Embodiments of a gasless eluent generator and methods for its use are described herein.

[0024] The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described in any way.

[0025] In this detailed description of various embodiments, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. However, those skilled in the art will understand that these various embodiments may be practiced without these specific details. In other instances, structures and devices are shown in block diagram form. Furthermore, those skilled in the art will readily understand that the specific order in which the methods are presented and performed is illustrative, and it is contemplated that the order may be changed and still remain within the spirit and scope of the various embodiments disclosed herein.

[0026] All literature and similar materials cited in this application, including but not limited to patents, patent applications, articles, books, papers, and Internet web pages, are expressly incorporated by reference in their entirety for any purpose. Unless otherwise explained, all technical and scientific terms used herein have the meaning commonly understood by one of ordinary skill in the art to which the various embodiments described herein belong.

[0027] There is an implicit "about" before temperatures, concentrations, times, pressures, flow rates, cross-sectional areas, etc. discussed in the present teachings, and thus it is understood that very small, minor deviations fall within the scope of the present teachings. In this application, the use of the singular includes the plural unless specifically stated otherwise. Similarly, the use of "comprises," "comprises," "comprising," "contain," "contains," "containing," "include," "includes," and "including" is not intended to be limiting. It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present teachings.

[0028] As used herein, "a" or "an" can refer to "at least one" or "one or more." Also, the use of "or" is inclusive, so that the phrase "A or B" is true when "A" is true, when "B" is true, or when both "A" and "B" are true. Further, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular.

[0029] A "system" refers to a set of components, whether real or abstract, in which each component interacts with or comprises a whole relative to at least one other component within the whole.

[0030] Chromatography Systems 1 illustrates an embodiment of a chromatography system 100. The chromatography system 100 may include a pump 102, an eluent generation module 104, a continuously regenerated trap column 106, 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 recycle line 120 may be used to transfer liquid from the outlet of the detector 116 to the inlet of the electrolytic suppressor 114, a recycle line 122 may be used to transfer liquid from the outlet of the electrolytic suppressor 114 to the inlet of the continuously regenerated trap column 106, and a recycle line 124 may be used to transfer liquid from the outlet of the continuously regenerated trap column 106 to waste.

[0031] The pump 102 can be configured to pump liquid from a liquid source 126 and be fluidically connected to the eluent generation module 104. In one embodiment, the liquid can be deionized water, an aqueous solution containing electrolyte(s), or a mixture of an organic solvent and deionized water or an aqueous solution of electrolyte(s). Some examples of electrolytes are sodium acetate and acetic acid. The eluent mixture containing an organic solvent can include a water-miscible organic solvent, such as methanol. The pump 102 can be configured to deliver liquid at pressures ranging from about 20 PSI to about 15,000 PSI. Under certain circumstances, pressures greater than 15,000 PSI can be implemented. Note that pressures shown herein are listed relative to ambient pressure (13.7 PSI to 15.2 PSI). The pump 102 can be in the form of a high-pressure liquid chromatography (HPLC) pump. Additionally, the pump 102 can be configured so that the liquid only contacts the inert portions of the pump 102, thereby preventing the leaching of significant amounts of impurities. In this context, significant means an amount of impurities that would interfere with the intended measurement. For example, the inert portions can be made of polyetheretherketone (PEEK), or at least coated with a PEEK lining, which does not leach a significant number of ions when exposed to the liquid.

[0032] An eluent is a liquid containing an acid, a base, a salt, or a mixture thereof that can be used to elute analytes through a chromatography column. Additionally, the eluent can include a mixture of a liquid and a water-miscible organic solvent, where the liquid may include an acid, a base, a salt, or a combination thereof. The eluent generation module 104 is configured to generate a generant. A generant refers to a specific type of acid, base, or salt that can be added to the eluent. In one embodiment, the generant can be a base, such as a cation hydroxide, or the generant can be an acid, such as carbonic acid, sulfuric acid, phosphoric acid, acetic acid, methanesulfonic acid (MSA), or a combination thereof. In various embodiments, the cation hydroxide can include potassium hydroxide, sodium hydroxide, lithium hydroxide, other alkali hydroxides, or any combination thereof.

[0033] 1, the eluent generator module 104 can be configured to receive liquid from the pump 102 and then add a generant to the liquid. The liquid containing the generant can be delivered from the eluent generator 104 to the inlet of a continuously regenerated trap column 106.

[0034] The optional continuously regenerated trap column 106 is configured to remove cationic or anionic contaminants from the eluent. The continuously regenerated trap column 106 can include an ion exchange bed with an electrode at the eluent outlet. An ion exchange membrane interface can separate the eluent from a second electrode, and contaminant ions can migrate through the ion exchange membrane to the second electrode. In various embodiments, anion removal can utilize an anion exchange bed with a cathode at the eluent outlet separated from the anode by an anion exchange membrane. Alternatively, cation removal can utilize a cation exchange bed with an anode at the eluent outlet separated from the cathode by a cation exchange membrane. The flowing eluent can be delivered from the continuously regenerated trap column 106 to the sample injector 110 with a substantial portion of the contaminants removed. Contaminant ions can be removed from the regenerative trap column 106 using liquid recycled via a recycle line 122 downstream of the electrolytic suppressor 114. The recycled liquid containing the removed contaminants may be discharged from the continuously regenerating trap column 106 via waste line 124 .

[0035] The sample injector 110 can be used to inject a bolus of liquid sample into the eluent stream. The liquid sample can include multiple chemical components (i.e., matrix components) and one or more analytes of interest.

[0036] The chromatographic separation column 112 can be used to separate various matrix components present in a liquid sample from the analytes of interest. Typically, the chromatographic separation column 112 can be in the form of a hollow cylinder containing a packed stationary phase. As the liquid sample flows through the chromatographic separation column 112, the matrix components and target analytes can have a range of retention times for elution from the chromatographic separation column 112. Depending on their properties, the target analytes and matrix components can have different affinities for the stationary phase of the chromatographic separation column 112. The outlet of the chromatographic separation column 112 can be fluidically connected to an electrolytic suppressor 114.

[0037] The electrolytic suppressor 114 can be used to reduce the eluent conductivity background and improve analyte response by efficiently exchanging eluent counterions with regenerant ions. The electrolytic suppressor 114 can 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 regenerant ions. The eluent suppression bed chamber can include an eluent flow path separated from the regenerant by an ion exchange barrier, allowing the eluent counterions to exchange with the regenerant ions across the ion exchange barrier. The cathode chamber or the anode chamber can be supplied with recycled liquid via a recycle line 120 downstream of the conductivity detector 116. The output of the electrolytic suppressor 114 can be fluidically connected to the detector 116 to measure the presence of separated chemical components in the liquid sample.

[0038] As shown in FIG. 1, the eluent output fluid from detector 116 is recycled to electrolytic suppressor 114 via recycle line 120, the output fluid of electrolytic suppressor 114 is recycled to continuously regenerated trap column 106 via recycle line 122, and the output fluid of continuously regenerated trap column 106 flows to waste via waste line 124.

[0039] The detector 116 may be in the form of a UV-visible spectrometer, a fluorescence spectrometer, an electrochemical detector, a conductivity detector, a charge detector, or a combination thereof. Details regarding charge detectors based on a charged barrier and two electrodes can be found in U.S. Pre-grant Publication No. 20090218238, which is incorporated herein by reference in its entirety. The detector 116 may also be in the form of a mass spectrometer or a charged particle detector, where the external stream of the regenerant recovery recycle line 120 is fed to an electrolytic suppressor 114. The charged particle detector atomizes the effluent stream, producing charged particles that can be measured as a current proportional to the analyte concentration. Details regarding charged particle detectors can be found in U.S. Patent Nos. 6,544,484 and 6,568,245, which are incorporated herein by reference in their entirety.

[0040] The electronic circuitry may include a microprocessor 118, a timer, and a memory portion. Additionally, the electronic circuitry may include a power supply configured to apply the respective control signals. The microprocessor 118 may be used to control the operation of the chromatography system 100. The microprocessor 118 may be integrated into the chromatography system 100 or may be part of a personal computer that communicates with the chromatography system 100. The microprocessor 118 may be configured to communicate with and control one or more components of the chromatography system, such as the pump 102, the eluent generator 104, the sample injector 110, and the detector 116. The memory portion may be used to store instructions for setting the magnitude and timing of the current waveform with respect to switching of the sample injector 110 to inject a sample.

[0041] 2 illustrates the operating principle of the eluent generation module 200. The eluent generation module 200 may include an electrolytic gas generator 202 and an electrolytic eluent generator 204. The electrolytic gas generator 202 may be configured to electrolytically generate dissolved gases, such as O or H, to react with the electrolytically generated gas from the electrolytic eluent generator 204, resulting in a substantially gas-free eluent. An embodiment of the electrolytic gas generator 202 is described in more detail in FIGS. 3A and 3B.

[0042] The electrolytic eluent generator 204 can include a high-pressure eluent generation chamber 206 and a low-pressure electrolyte reservoir 208. In various embodiments, the high-pressure generation chamber 206 can operate at a pressure greater than about 2,000 psi, such as at least about 5,000 psi, or even at least about 10,000 psi, and up to about 30,000 psi, such as up to about 15,000 psi.

[0043] The eluent generation chamber 206 can include a perforated platinum (Pt) electrode 210. The electrolyte reservoir 208 can include a Pt electrode 212 and an electrolyte solution 214. In various embodiments, the electrolytic eluent generator 204 can generate a base such as potassium hydroxide (KOH), sodium hydroxide (NaOH), or lithium hydroxide (LiOH). The electrode 210 can be a cathode where hydroxide ions can be formed, and the electrode 212 can be an anode. In other embodiments, the electrolytic eluent generator 204 can generate an acid such as carbonic acid, sulfuric acid, phosphoric acid, acetic acid, or methanesulfonic acid, and the electrode 210 can be an anode where hydronium ions can be formed, and the electrode 212 can be a cathode. The eluent generation chamber 206 can be connected to the electrolyte reservoir 208 by an exchange connector 216, which can allow the passage of ions of only one charge from the electrolyte reservoir 208 to the high-pressure generation chamber 206. The exchange connector 216 can also serve the important role of a high-pressure physical barrier between the low-pressure electrolyte reservoir 208 and the high-pressure production chamber 206. In various embodiments in which the electrolytic eluent generator 204 is a base generator, the exchange connector 216 can allow the passage of cations while substantially preventing the passage of anions from the electrolyte reservoir 208 to the production chamber 206. In alternative embodiments in which the electrolytic eluent generator 204 is an acid generator, the exchange connector 216 can allow the passage of anions while substantially preventing the passage of cations from the electrolyte reservoir 208 to the production chamber 206.

[0044] In various embodiments, the eluent generation chamber 206 and the ion exchange connector 216 can be incorporated into an eluent generation cartridge.

[0045] To generate a basic eluent such as KOH, NaOH, or LiOH, deionized water can be pumped through the eluent generation chamber 206 and a DC current can be applied across electrodes 210 and 212. Under an applied electric field, electrolysis of water can occur at both electrodes 210 and 212 of the electrolytic eluent generator 204. H + Water can be oxidized to form ions and oxygen gas: HO → 2H + +1 / 2O2↑+2e - Water can be reduced to form OH ions and hydrogen gas at electrode 210 in the eluent generation chamber 206: 2H2O + 2e - →2OH - +H2↑. H generated at the anode 212 + ions in the electrolyte reservoir 208 + To displace the ions, the displaced ions can travel across the cation exchange connector 216 to the eluent generation chamber 206. + The ions can combine with hydroxide ions produced at the cathode 210 to produce a KOH solution, which can be used as an eluent for anion exchange chromatography. Additionally, oxygen gas produced by the electrolytic gas generator 202 can react with hydrogen gas formed at the electrode 210 to form water, thereby substantially removing the electrolytically produced gas from the eluent stream. The concentration of KOH produced can be determined by the current applied to the electrolytic eluent generator 204 and the flow rate of water as a carrier through the production chamber 206. Additionally, the current applied to the electrolytic gas generator 202 can be adjusted to stoichiometrically match the amount of oxygen gas produced by the electrolytic gas generator 202 with the amount of hydrogen gas produced at the cathode 210.

[0046] Deionized water can be pumped through the eluent generation chamber 206 and a DC current can be applied across electrodes 210 and 212 to generate an acid eluent, such as carbonic acid, sulfuric acid, phosphoric acid, acetic acid, or methanesulfonic acid. Under the applied field, electrolysis of water can occur at both electrodes 210 and 212 of the electrolytic eluent generator 204. Water can be oxidized to form H ions and oxygen gas at electrode 210 in the methanesulfonic acid generation chamber 206: HO → 2H + +1 / 2O2↑+2e - Water can be reduced to form OH ions and hydrogen gas at the electrode 212 in the electrolyte reservoir 208: 2H2O + 2e - →2OH - +H2↑. OH generated at electrode 212 - As the ions displace the methanesulfonate ions in the electrolyte reservoir 208, the displaced ions can migrate across the anion exchange connector 216 to the eluent generation chamber 206. These methanesulfonate ions can combine with the hydronium ions generated at the electrode 210 to produce a methanesulfonic acid solution, which can be used as an eluent for cation exchange chromatography. Additionally, hydrogen gas produced by the electrolytic gas generator 202 can react with oxygen gas formed at the electrode 210 to form water, thereby substantially removing the electrolytically produced gas from the eluent stream. The concentration of the produced methanesulfonic acid can be determined by the current applied to the electrolytic eluent generator 204 and the flow rate of water as a carrier through the generation chamber 206. Additionally, the current applied to the electrolytic gas generator 202 can be adjusted to stoichiometrically match the hydrogen gas production rate of the electrolytic gas generator 202 with the oxygen gas production rate of the anode 210.

[0047] 3A shows an electrolytic gas generator 300 for use with an electrolytic eluent generator to generate a basic eluent, such as KOH, NaOH, or LiOH. The electrolytic gas generator 300 includes a production chamber 302 and a bulk solvent chamber 304. The production chamber 302 has an inlet 306 for receiving a liquid and an outlet 308 for supplying the liquid to the electrolytic eluent generator. A Pt anode 310 can be located at the outlet of the production chamber, and a Pt cathode 312 can be located within the bulk solvent chamber 304. A cation exchange connector 314 can separate the production chamber 302 from the bulk solvent chamber 304.

[0048] A DC current can be applied across the Pt anode 310 and the Pt cathode 312. Under an applied electric field, electrolysis of water can occur at both the Pt anode 310 and the Pt cathode 312. H + Water can be oxidized to form ions and oxygen gas: HO → 2H + +1 / 2O2↑+2e - OH at the Pt cathode 312 in the bulk solvent chamber 304 - Water can be reduced to form ions and hydrogen gas: 2H2O + 2e- → 2OH- + H2↑. H generated at the Pt anode 310 + The ions can migrate across the cation exchange connector 314 into the bulk solvent chamber 304. These H +The ions can combine with hydroxide ions produced at the Pt cathode 312 to produce water. Additionally, oxygen gas produced at the Pt anode 310 enters the eluent stream and flows into the electrolytic eluent generator, where it can react with hydrogen gas electrolytically produced by the electrolytic eluent generator to form water, substantially removing the gas from the eluent stream. The amount of oxygen gas can be determined by the current applied to the electrolytic gas generator 300 and the flow rate of water as a carrier through the production chamber 302. The amount of oxygen gas produced can be matched to the amount of hydrogen gas produced by the electrolytic eluent generator, thereby allowing stoichiometric amounts of oxygen gas and hydrogen gas to react in the electrolytic eluent generator.

[0049] 3B shows an electrolytic gas generator 350 used in conjunction with an electrolytic eluent generator to produce an acid eluent, such as carbonic acid, sulfuric acid, phosphoric acid, acetic acid, or methanesulfonic acid. The electrolytic gas generator 350 includes a production chamber 352 and a bulk solvent chamber 354. The production chamber 352 has an inlet 356 for receiving a liquid and an outlet 358 for supplying the liquid to the electrolytic eluent generator. A Pt cathode 360 ​​can be located at the outlet of the production chamber, and a Pt anode 362 can be located within the bulk solvent chamber 354. An anion exchange connector 314 can separate the production chamber 352 from the bulk solvent chamber 354.

[0050] A DC current can be applied across the Pt anode 362 and the Pt cathode 360. Under an applied electric field, electrolysis of water can occur at both the Pt anode 362 and the Pt cathode 360. H + Water can be oxidized to form ions and oxygen gas: HO → 2H + +1 / 2O2↑+2e - OH is generated at the Pt cathode 360 ​​in the generation chamber 352. - Water can be reduced to form ions and hydrogen gas: 2H2O + 2e - →2OH- +H2↑. OH generated at Pt cathode 360 -The ions can migrate across the anion exchange connector 364 into the bulk solvent chamber 354. - The ions can combine with hydroxide ions generated at the Pt anode 362 to produce water. Additionally, hydrogen gas produced at the Pt cathode 360 ​​enters the eluent stream and flows into the electrolytic eluent generator, where it can react with oxygen gas electrolytically produced by the electrolytic eluent generator to form water, substantially removing the gas from the eluent stream. The amount of hydrogen gas can be determined by the current applied to the electrolytic gas generator 350 and the flow rate of water as a carrier through the generation chamber 352. The amount of hydrogen gas produced can be matched to the amount of oxygen gas produced by the electrolytic eluent generator, thereby allowing stoichiometric amounts of oxygen and hydrogen gas to react in the electrolytic eluent generator.

[0051] Figure 4 is a flow diagram of a method for producing and using a gas-free base eluent. At 402, a liquid stream can be provided to the inlet of an electrolytic gas generator, such as electrolytic gas generator 300 of Figure 3A. At 404, a DC current can be applied across the outlet anode and bulk solvent chamber cathode to produce O2 at the outlet anode and pump the O2 into the liquid stream.

[0052] At 406, the liquid stream containing oxygen gas is sent to an electrolytic eluent generator, such as electrolytic eluent generator 204 of FIG. 2. At 408, a DC current is applied across the electrolyte chamber anode and the eluent generation chamber cathode to generate K + , Na + , or Li + Electrolyte ions such as , can be transported from the electrolyte chamber across a cation exchange connector to form a base eluent in the eluent generation chamber. At 410, oxygen can react with hydrogen formed at the eluent generation chamber cathode to produce a gas-free base eluent.

[0053] At 412, the concentration of base in the gas-free base eluent can be varied by varying the DC current applied to the eluent generation chamber. Additionally, by varying the DC current applied to the electrolytic gas generator, the amount of oxygen produced by the electrolytic gas generator can be matched to the amount of hydrogen produced in the electrolytic eluent generator.

[0054] At 414, a sample can be injected into an eluent stream supplied to a chromatography column, the sample can be at least partially retained by the chromatography column, and the sample analytes can be eluted from the chromatography column using a gas-free base eluent with varying concentrations of base. The sample analytes can be detected using a detector and / or analyzed by a mass spectrometer.

[0055] Figure 5 is a flow diagram of a method for producing a gas-free acid eluent. At 502, a liquid stream can be fed to the inlet of an electrolytic gas generator, such as electrolytic gas generator 350 of Figure 3B. At 504, a DC current can be applied across the outlet cathode and bulk solvent chamber anode to produce H2 at the outlet cathode and pump the H2 into the liquid stream.

[0056] At 506, the liquid stream containing hydrogen gas is sent to an electrolytic eluent generator, such as electrolytic eluent generator 204 of FIG. 2. At 508, a DC current can be applied across the electrolyte chamber cathode and the eluent generation chamber anode to migrate electrolyte ions, such as carbonate, phosphate, acetate, or methanesulfonate, from the electrolyte chamber across the anion exchange connector to form an acid eluent in the eluent generation chamber. At 510, the hydrogen can react with oxygen formed at the eluent generation chamber anode to produce a gas-free base eluent.

[0057] At 512, the concentration of acid in the gas-free acid eluent can be varied by varying the DC current applied to the eluent generation chamber. Additionally, the DC current applied to the electrolytic gas generator can be varied to match the amount of hydrogen produced by the electrolytic gas generator with the oxygen formed in the electrolytic eluent generator.

[0058] At 514, a sample can be injected into an eluent stream that is supplied to a chromatography column. The sample can be at least partially retained by the chromatography column, and the sample analytes can be eluted from the chromatography column using a gas-free acid eluent with varying concentrations of acid. The sample analytes can be detected using a detector and / or analyzed by a mass spectrometer.

[0059] Example 1 is an eluent generation module for producing a gas-less base eluent (KOH). The outlet of the eluent generation module is directed to a gas collection device to measure the amount of gas in the eluent. Table 1 shows the measured gas amount after 10 minutes for different voltage settings of the electrolytic gas generator and electrolytic eluent generator. [Table 1]

[0060] Example 2 is an eluent generation module for producing a gasless base eluent (MSA). The outlet of the eluent generation module is directed to a gas collection device to measure the amount of gas in the eluent. Table 1 shows the measured gas amount after 10 minutes for different voltage settings of the electrolytic gas generator and electrolytic eluent generator. [Table 2]

[0061] While the present teachings are described in conjunction with various embodiments, it is not intended that the present teachings be limited to such embodiments. Rather, the present teachings encompass various alternatives, modifications, and equivalents, as will be appreciated by those skilled in the art.

[0062] Furthermore, in describing various embodiments, the specification may present methods and / or processes in terms of a particular order. However, to the extent that the method or process does not rely on the particular order of steps described herein, the method or process should not be limited to the particular order of steps described. As one of ordinary skill in the art will understand, other orders of steps may be possible. Thus, the particular order of steps described herein should not be construed as a limitation on the claims. In addition, claims directed to the method and / or process should not be limited to performing those steps in the order written; one of ordinary skill in the art will readily understand that the order may be changed and still remain within the spirit and scope of the various embodiments.

Claims

1. An eluent generation module, An electrolytic gas generator comprising a generation chamber having an inlet and an outlet, an outlet electrode in the generation chamber, a first ion exchange connector, a bulk solvent chamber separated from the generation chamber by the ion exchange connector, and a bulk solvent chamber electrode in the bulk solvent chamber, An electrolytic eluent generator provided on the fluid downstream side of the electrolytic gas generator, comprising an electrolyte chamber for containing an electrolyte aqueous solution, an electrolyte chamber electrode within the electrolyte chamber, a second ion exchange connector, an eluent generation chamber separated from the electrolyte chamber by the second ion exchange connector, and an eluent generation chamber electrode, Includes, An eluent generation module wherein the liquid discharged from the outlet of the electrolytic gas generator contains the electrolytic gas generated in the generation chamber and is supplied to the electrolytic eluent generator, and the electrolytic gas sent from the electrolytic gas generator is combined with the electrolytic gas generated at the eluent generation chamber electrode in the eluent generation module.

2. The eluent generation module according to claim 1, wherein the electrolytic eluent generator is configured to generate an acid eluent, the second ion exchange connector includes an anion exchange barrier, the electrolyte chamber electrode is a cathode, and the eluent generation chamber electrode is an anode.

3. The electrolytic gas generator, at the outlet, H 2 This generates the O produced by the electrode in the eluent generation chamber. 2 The eluent generation module according to claim 2, configured to bond with, wherein the first ion exchange connector includes an anion exchange barrier, the outlet electrode is a cathode, and the bulk solvent chamber electrode is an anode.

4. The eluent generating module according to claim 2, wherein the electrolyte aqueous solution comprises carbonic acid, sulfuric acid, phosphoric acid, acetic acid, methanesulfonic acid, or any combination thereof.

5. The eluent generation module according to claim 2, wherein the generation chamber includes an anion ion exchange bed.

6. The eluent generation module according to claim 1, wherein the eluent generation module is configured to generate a base eluent, the second ion exchange connector includes a cation exchange barrier, the electrolyte chamber electrode is an anode, and the eluent generation chamber electrode is a cathode.

7. The electrolytic gas generator, at the outlet, 2 This generates H produced by the electrode in the eluent generation chamber. 2 The eluent generation module according to claim 6, configured to bond with, wherein the first ion exchange connector includes a cation exchange barrier, the outlet electrode is an anode, and the bulk solvent chamber electrode is a cathode.

8. The eluent generating module according to claim 6, wherein the electrolyte aqueous solution comprises potassium hydroxide, sodium hydroxide, lithium hydroxide, other alkali hydroxides, or any combination thereof.

9. The eluent generation module according to claim 2, wherein the generation chamber includes an anion ion exchange bed.

10. The eluent generation module according to claim 1, wherein the outlet electrode is a perforated platinum electrode.

11. A method for producing a gas-free base eluent, The supply of liquid to the inlet of an electrolytic gas generator, wherein the electrolytic gas generator includes a generation chamber having the inlet and outlet, an outlet anode in the generation chamber, a first cation exchange connector, a bulk solvent chamber separated from the generation chamber by the cation exchange connector, and a bulk solvent chamber cathode in the bulk solvent chamber. A current is applied across the outlet anode and the bulk solvent chamber cathode, and O 2 To generate, The liquid flow exiting the outlet of the electrolytic gas generator is directed towards an electrolytic eluent generator provided on the fluid downstream side of the electrolytic gas generator, wherein the liquid flow contains the generated O2, and the electrolytic eluent generator includes an electrolyte chamber containing an aqueous electrolyte solution, an electrolyte chamber anode within the electrolyte chamber, a second cation exchange connector, an eluent generation chamber separated from the electrolyte chamber by the second cation exchange connector, and an eluent generation chamber cathode. A current is applied across the electrolyte chamber anode and the eluent generation chamber cathode to move electrolyte ions from the electrolyte chamber to the second cation exchange connector, thereby forming a base eluent in the eluent generation chamber. The aforementioned O 2 H formed in the eluent generation chamber cathode 2 A method comprising reacting with to produce a base eluent that does not contain the gas.

12. The method according to claim 11, wherein the electrolyte aqueous solution comprises potassium hydroxide, sodium hydroxide, lithium hydroxide, other alkali hydroxides, or any combination thereof.

13. The method according to claim 11, wherein the outlet anode is a porous platinum anode.

14. The method according to claim 11, wherein the base eluent that does not contain the aforementioned gas contains less than about 0.2 mL of gas per 1 mL of eluent.

15. The method according to claim 14, wherein the base eluent that does not contain the aforementioned gas contains less than about 0.1 mL of gas per mL of eluent.

16. The method according to claim 15, wherein the base eluent that does not contain the aforementioned gas contains less than approximately 0.05 mL of gas per 1 mL of eluent.

17. The process involves injecting the sample into a chromatography column, The current applied across the generation chamber anode and the bulk solvent chamber cathode of the electrolytic gas generator is changed, the current applied across the electrolyte chamber anode and the eluent generation chamber cathode is changed, and the concentration of the gas-free base eluent is changed. The gas-free base eluent is supplied to the chromatography column, Eluting the sample analyte from the aforementioned chromatography column, The method according to claim 11, further comprising detecting the sample analyte using a detector.

18. A method for producing an acid eluent that does not contain gas, The supply of liquid to the inlet of an electrolytic gas generator, wherein the electrolytic gas generator includes a generation chamber having the inlet and outlet, an outlet cathode within the generation chamber, a first anion exchange connector, a bulk solvent chamber separated from the generation chamber by the anion exchange connector, and a bulk solvent chamber anode within the bulk solvent chamber. A current is applied across the outlet cathode and the bulk solvent chamber anode, so that H is present at the outlet cathode. 2 To generate, The liquid flow exiting the outlet of the electrolytic gas generator is directed towards an electrolytic eluent generator provided on the fluid downstream side of the electrolytic gas generator, wherein the liquid flow contains the generated H2, and the electrolytic eluent generator includes an electrolyte chamber containing an aqueous electrolyte solution, an electrolyte chamber cathode within the electrolyte chamber, a second anion exchange connector, an eluent generation chamber separated from the electrolyte chamber by the second anion exchange connector, and an eluent generation chamber anode. A current is applied across the electrolyte chamber cathode and the eluent generation chamber anode, causing electrolyte ions to move from the electrolyte chamber across the second anion exchange connector to form an acid eluent in the eluent generation chamber. Reacting the H formed at the eluent generation chamber anode with O to produce an acid eluent free of the gas, the method comprising. 2 O 2 and producing an acid eluent free of the gas, the method comprising.

19. The method according to claim 18, wherein the aqueous electrolyte solution comprises carbonic acid, sulfuric acid, phosphoric acid, acetic acid, methanesulfonic acid, or any combination thereof.

20. The method according to claim 18, wherein the outlet electrode is a perforated platinum electrode.

21. The method according to claim 18, wherein the gas-free acid eluent contains less than approximately 0.2 mL of gas per 1 mL of eluent.

22. The method according to claim 21, wherein the gas-free acid eluent contains less than approximately 0.1 mL of gas per mL of eluent.

23. The method according to claim 22, wherein the gas-free acid eluent contains less than approximately 0.05 mL of gas per 1 mL of eluent.

24. The process involves injecting the sample into a chromatography column, The current applied across the generating chamber cathode and the bulk solvent chamber anode of the electrolytic gas generator is changed, and the current applied across the electrolyte chamber cathode and the eluent generating chamber anode is changed to change the concentration of the gas-free acid eluent, The acid eluent that does not contain the aforementioned gas is supplied to the chromatography column, Eluting the sample analyte from the aforementioned chromatography column, The method according to claim 18, further comprising detecting the sample analyte using a detector.

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