EP0032770A2 — Apparatus for chromatographic ion analysis and me…

Claim 1

Independent Claim 142 words

Apparatus for chromatographic analysis comprising an eluent reservoir, a chromatographic separating means in communication with said reservoir for receiving eluent containing an electrolyte in solution therefrom, said separating means including a separating medium useful for separating ionic species of a sample eluted therethrough, a stripper device communicating with said separating means for treating effluent eluted therefrom! said stripper device comprising a strong acid or strong base ion-exchange membrane for partitioning a regenerant from the effluent of the separating means, said membrane being preferentially permeable to ions of the same charge as exchangeable ions of said membrane, the exchangeable ions of said membrane provided by the regenerant being of the form to convert the electrolyte of the eluent to a weakly ionized form, and a detector means for detecting resolved ionic species communicating with the stripper device for receiving the treated effluent therefrom.

Claim 2

Dependent Claim 142 words

Apparatus for chromatographic analysis comprising an eluent reservoir, a chromatographic separating means in communication with said reservoir for receiving eluent containing an electrolyte in solution therefrom, said separating means including a separating medium useful for separating ionic species of a sample eluted therethrough, a stripper device communicating with said separating means for treating effluent eluted therefrom! said stripper device comprising a strong acid or strong base ion-exchange membrane for partitioning a regenerant from the effluent of the separating means, said membrane being preferentially permeable to ions of the same charge as exchangeable ions of said membrane, the exchangeable ions of said membrane provided by the regenerant being of the form to convert the electrolyte of the eluent to a weakly ionized form, and a detector means for detecting resolved ionic species communicating with the stripper device for receiving the treated effluent therefrom.

Claim 3

Dependent Claim 18 words

The apparatus of Claim 1 wherein said membrane is in the form of one or more hollow fibers.

Claim 4

Dependent Claim 41 words

- The apparatus of Claim 1, wherein said membrane comprises at least one hollow fiber immersed within a moving stream of said regenerant, the bore of said hollow fiber being in communication with said separating means for receiving the effluent therefrom.

Claim 5

Dependent Claim 27 words

The apparatus of Claim 1, 2 or 3 including a reservoir for said regenerant, and means for conveying said regenerant from the reservoir to the stripper device.

Claim 6

Dependent Claim 24 words

The apparatus of Claim 4 wherein said conveying means provides for countercurrent flow of effluent with respect to the regenerant through the hollow fiber.

Claim 7

Dependent Claim 24 words

The apparatus of Claim 1 wherein the strong acid ion exchange membrane is of a synthetic resinous material and in the hydrogen ion form.

Claim 8

Dependent Claim 18 words

The apparatus of Claim 1 wherein said membrane is selected from a sulfonated or aminated synthetic resinous material.

Claim 9

Dependent Claim 23 words

The apparatus of Claim 1 wherein the strong base ion-exchange membrane is of a synthetic resinous material and in the hydroxide ion form.

Claim 10

Independent Claim 20 words

The apparatus of any one of the preceding claims, wherein said detector means comprises a flow through electrical conductivity cell.

Claim 11

Dependent Claim 21 words

The apparatus of Claim 6, 7 or 8 wherein said membrane is selected from a polyethylene homopolymer or a fluorinated polymer.

Claim 12

Dependent Claim 182 words

Method of chromatographic ion analysis comprising the steps of eluting a sample of predetermined volume and containing ionic species to be determined through a separating medium effective to separate the ionic species with the aid of an eluent comprising an electrolyte in solution, thereafter contacting the effluent eluting from the separating medium with a strong acid or strong base ion-exchange membrane which is permeable to ions of the same charge as the exchangeable ions of said membrane and which resists permeation therethrough of ions of the opposite charge, and simultaneously contacting the membrane with a regenerant, said membrane forming a permselective partition between the regenerant and said effluent, whereby ions exchanged from the effluent at the active ion-exchange sites of the membrane are diffused through the membrane and are exchanged with ions of said regenerant, and are thus diffused ultimately into said regenerant, said exchangeable ions of the ion-exchange membrane being in that form needed to convert said electrolyte of the eluent to a weakly ionized form, and including the step of detecting a resolved ionic species contained in said treated effluent.

Claim 13

Dependent Claim 182 words

Method of chromatographic ion analysis comprising the steps of eluting a sample of predetermined volume and containing ionic species to be determined through a separating medium effective to separate the ionic species with the aid of an eluent comprising an electrolyte in solution, thereafter contacting the effluent eluting from the separating medium with a strong acid or strong base ion-exchange membrane which is permeable to ions of the same charge as the exchangeable ions of said membrane and which resists permeation therethrough of ions of the opposite charge, and simultaneously contacting the membrane with a regenerant, said membrane forming a permselective partition between the regenerant and said effluent, whereby ions exchanged from the effluent at the active ion-exchange sites of the membrane are diffused through the membrane and are exchanged with ions of said regenerant, and are thus diffused ultimately into said regenerant, said exchangeable ions of the ion-exchange membrane being in that form needed to convert said electrolyte of the eluent to a weakly ionized form, and including the step of detecting a resolved ionic species contained in said treated effluent.

Claim 14

Dependent Claim 18 words

The method of Claim 11 wherein said membrane is continuously contacted by a flowing stream of fresh regenerant.

Claim 15

Dependent Claim 18 words

The method of Claim 11 wherein said membrane is in the form of one or more hollow fibers.

Claim 16

Dependent Claim 47 words

The method of Claim 11 including the step of routing the effluent from the separating means through the internal bores of one or more hollow fibers in a direction countercurrent to the flow of regenerant, said resolved ionic species being detected by measuring the electrical conductivity thereof.

Claim 17

Independent Claim 47 words

The method of any one of Claims 11 to 14 wherein said membrane is selected from a strong acid ion-exchanger in the hydrogen ion form, a sulfonated polyolefin, a sulfonated fluoropolymer, a strong base ion-exchanger in the hydroxide ion form, an aminated polyolefin, or an aminated fluoropolymer.

Apparatus for chromatographic ion analysis and method of chromatographic ion analysis

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