Abstract: An ion exchange resin for use as a stationary phase in an ion chromatography column. The ion exchange resin has a negatively charged substrate particle, a positively charged polymer layer bound to the negatively charged substrate particle, a linker, and an ion exchange group. The ion exchange group includes a sulfonamide group and an amine, in which the ion exchange group is coupled to the positively charged polymer layer via the linker. When the sulfonamide is in a neutral form, a positively charged amine group provides retention; while when the sulfonamide is in an anionic form, the sulfonamide anion becomes a counter ion to the positively charged amine group, forming a zwitterion that reduces retention at that site. Accordingly, the retention time is able to be controlled by adjusting the mobile phase pH.

Abstract: A chromatographic media for separating bio-polymers, the chromatographic media having cationic exchange properties and anionic exchange properties, the chromatographic media comprising: (a) non-porous substrate particles including an organic polymer, the substrate particles having a neutral hydrophilic layer at a surface of the non-porous substrate particles, in which the neutral hydrophilic layer is configured to reduce a binding of the bio-polymers directly to the non-porous substrate particles compared to a binding of the bio-polymer to the non-porous substrate particles without the neutral hydrophilic layer; (b) a charged first ion exchange layer bound to the substrate particles on top of the hydrophilic layer, the first ion exchange layer comprising first ion exchange groups; and (c) a charged second ion exchange layer bound to the substrate particles on top of the first ion exchange layer.

Abstract: Systems and methods for inhibiting translocation of ions across ion exchange barriers include an eluent generator having an ion source reservoir with a first electrode, an eluent generation chamber with a second electrode, an ion exchange barrier disposed therebetween, and means for reversing the polarity of a voltage or current applied across the first and second electrodes. A first polarity voltage or current applied across the electrodes generates an electric field that promotes translocation of eluent counter ions from the reservoir across the barrier, where the counter ions combine with eluent ions electrolytically generated in the chamber. By reversing the polarity of the voltage or current across the electrodes, the resulting electric field inhibits translocation of counter ions across the barrier from the reservoir into the chamber. Reverse voltage or current bias reduces counter ion concentration in the resting chamber to prevent exhaustion of ion suppressor capacity during start up.

Abstract: A vial cap for removing a matrix component from a liquid sample is described. The vial cap includes a cap body, an inlet portion, and an outlet portion. The cap body is configured to have a slidable gas and liquid seal with a side wall of a sample vial. The inlet portion includes a counterbore section that holds a filter plug. The filter plug includes a polyethylene resin and a material selected from the group consisting of an ion exchange material and a reversed-phase material. The vial cap is adapted for solid phase extraction for use in an autosampler with a plurality of sample vials.

Abstract: A method for making modified latex particles, wherein the particles comprise condensation polymers bonded to functional groups on the latex particles and the method for forming the condensation polymer comprises reacting the amino groups present on the latex particles with (i) at least a first polyfunctional compound, having at least two functional moieties reactive with said functional groups of the latex, or (ii) at least a first polyfunctional compound, having at least two functional moieties reactive with said functional groups of the latex and at least a first amine compound, comprising amino groups selected from the group consisting of ammonia, a primary and a secondary amine to form a first condensation polymer reaction product comprising ion exchanging sites and a first unreacted excess of functional moieties.

Abstract: A pH gradient mobile phase preparation kit is described. The preparation kit includes a first component and a second component. The first component includes a first reagent separate from a second reagent. The first reagent, the second reagent, and a solvent together provide a volatile buffer solution having a low pH. The second component includes a base. The base mixed in the solvent provide a volatile base solution having a high pH. A method of separating and detecting one or more analytes comprised in a matrix of components in a sample, using the kit is also described.

Abstract: An electrochemical cell comprises a chamber, an inlet port, an outlet port, an electrode port, and a counter electrode. The inlet port is configured to allow flow of a liquid into the chamber and through an inlet opening toward the working electrode, and the outlet port is configured to allow flow of a liquid out of the chamber and through an outlet opening. The device is configured so that a force applied to the working electrode slides the first end face of the working electrode to a distance from a face of the inlet opening due to the balancing force of a fluid flowing out of the inlet opening. The device may be used in a method for analyzing an analyte, such as one or more amino acids in a liquid sample.

Abstract: The present invention relates to a coated ion exchange substrate suitable for use in chromatography medium and methods of making thereof.

Abstract: An electrolytic eluent generator includes an electrolyte reservoir, an eluent generation chamber, and an ion exchange membrane stack. The electrolyte reservoir includes a chamber containing an aqueous electrolyte solution including an electrolyte; and a first electrode. The eluent generation chamber including a second electrode. The ion exchange connector includes an ion exchange membrane stack, and a compression block.

Abstract: A coated substrate that comprises a polyolefin substrate having a functional polymer layer disposed thereon. The polyolefin substrate has a flow through pore structure with a pore size ranging from about 5 microns to about 250 microns. The functional polymer layer has a thickness ranging from about 1 micron to about 20 microns and a layer pore structure having a pore size ranging from about 1 nm to about 100 nm.

Abstract: An anion exchange for separating a plurality of carbohydrates includes a negatively charged substrate particle. A base polymer layer includes a first plurality of quaternary amines. The polyalkylpolyamine polymer layer is covalently attached to the base condensation polymer layer. The polyalkylpolyamine polymer layer includes a polymeric branch structure that includes a second plurality of quaternary amines. A density of the second plurality of quaternary amines increases in a direction away from the base condensation polymer layer. The anion exchange stationary phase does not have a hydroxy group spaced apart from any one of the first or the second plurality of quaternary amines by an ethyl group.

Abstract: A method of separating analytes in a liquid sample includes flowing the liquid sample through a chromatography column configured for use in liquid chromatography. The chromatography column contains a composition that includes a solid support having an exterior surface, a ligand, and a linker. The ligand includes a polyhedral oligomeric silsesquioxane moiety. The linker is covalently bound to both the polyhedral oligomeric silsesquioxane moiety and the exterior surface of the solid support.

Abstract: An apparatus for suppressing an eluent of an aqueous sample stream including analyte ions of one charge, positive or negative, comprises a primary channel member, a first block, a first regenerant flow channel, a first charged barrier, a second block, a second regenerant flow channel, a second charged barrier, a first stationary flow-through ion exchange material, and optionally a first electrode and a second electrode. The first stationary flow-through ion exchange material comprises a polyolefin substrate having a functional polymer layer disposed thereon. The polyolefin substrate has a pore structure with a pore size ranging from about 5 microns to about 250 microns. The functional polymer layer has a thickness ranging from about 1 micron to about 20 microns, and a layer pore structure having a pore size ranging from about 1 nm to about 100 nm. The functional polymer layer comprises an ion exchange layer.

Abstract: An electrolytic eluent generator includes an electrolyte reservoir, an eluent generation chamber, and an ion exchange membrane stack. The electrolyte reservoir includes a chamber containing an aqueous electrolyte solution including an electrolyte; and a first electrode. The eluent generation chamber including a second electrode. The ion exchange connector includes an ion exchange membrane stack, and a compression block.

Abstract: Ion exchange stationary phases are prepared with diprimary diamines for applications such as separating samples that contain polyvalent anions. The ion exchange stationary phase includes a series of condensation polymer reaction products bound to a substrate. The condensation polymer products are formed with diprimary diamines and polyepoxide compounds. The ion exchange stationary phases described herein are capable of separating monovalent and highly polyvalent anions relatively quickly with relatively low eluent concentrations in one chromatographic run.

Abstract: Ion exchange stationary phases are prepared with diprimary diamines for applications such as separating samples that contain polyvalent anions. The ion exchange stationary phase includes a series of condensation polymer reaction products bound to a substrate. The condensation polymer products are formed with diprimary diamines and polyepoxide compounds. The ion exchange stationary phases described herein are capable of separating monovalent and highly polyvalent anions relatively quickly with relatively low eluent concentrations in one chromatographic run.

Abstract: A coated substrate that comprises a polyolefin substrate having a functional polymer layer disposed thereon. The polyolefin substrate has a flow through pore structure with a pore size ranging from about 5 microns to about 250 microns. The functional polymer layer has a thickness ranging from about 1 micron to about 20 microns and a layer pore structure having a pore size ranging from about 1 nm to about 100 nm.

Abstract: An ion exchange chromatographic packing material is described that includes support resin particles and a copolymer grafted to the support resin particles. The copolymer includes polymerized functional monomers such as a first ion exchange group monomer and a second ion exchange group monomer. At a first pH, the first ion exchange group monomer is configured to have a first charge at a first pH, and the second ion exchange group monomer is configured to have a net neutral charge. At a second pH, the first ion exchange group monomer is configured to have the first charge at a second pH, and the second ion exchange group monomer is configured to have a second charge at the second pH where the first charge and second charge both have a same polarity.

Abstract: Open tubular capillary columns for liquid and ion chromatography, based upon an ionically impermeable polyolefin capillary having a bore with a sulfonate-group- or amine-group-functionalized internal surface. The capillary columns may include a coating of ion exchanging nanoparticles electrostatically bound to the functionalized internal surface. The capillary columns may be made by exposing the interior surface to a sulfonating reagent comprising chlorosulfonic acid (ClSO3H), preferably from 85 wt % to 95 wt % chlorosulfonic acid at a process temperature of 20 to 25° C. The interior surface may be subsequently exposed to an asymmetrical diamine to form a sulfonic mid-linkage to the diamine, i.e., to form a sulfonamide-linked, amine-group-functionalized internal surface. The coating may be provided by subsequently exposing the interior surface to an aqueous suspension of ion exchanging nanoparticles to electrostatically bond the ion exchanging nanoparticles to the functionalized internal surface.

Abstract: An electrochemical cell comprises a chamber, an inlet port, an outlet port, an electrode port, and a counter electrode. The inlet port is configured to allow flow of a liquid into the chamber and through an inlet opening toward the working electrode, and the outlet port is configured to allow flow of a liquid out of the chamber and through an outlet opening. The device is configured so that a force applied to the working electrode slides the first end face of the working electrode to a distance from a face of the inlet opening due to the balancing force of a fluid flowing out of the inlet opening. The device may be used in a method for analyzing an analyte, such as one or more amino acids in a liquid sample.