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US5366601A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for separating ionic species using capillary electrophoresis

Assignee: Waters Technologies Corp
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Filing: 1992-10-20
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Granted: 1994-11-22
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Expires: 2012-10-20
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Abstract

Abstract A technique for separating, identifying and measuring ions in solution by capillary zone electrophoresis is described, which provides improved sensitivity and resolution of anionic species. The method involves introducing a sample containing the ionic species into a narrow bore capillary filled with a carrier electrolyte containing a selected light-absorbing anion. An electrical potential is applied across the capillary column causing the ions to elute according to their ionic mobility. Both UV absorbing and UV-transparent ions can be detected and quantitated by UV/visible photometric monitoring.

Inventors

  • 👤 William R. Jones
  • 👤 Petr Jandik

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 14:08
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/447; G01N27/44704; G01N27/44717; G01N27/44721

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 90 words
A method for detecting anions in a sample using capillary zone electrophoresis comprising the steps of: a) introducing the sample into a capillary; b) immersing the capillary in a carrier electrolyte containing a salt selected from the group consisting of molybdate, tungstate, ferrocyanide, ferricyanide, bromide, iodide and dichromate; c) applying an electrical current under conditions appropriate for the anions in the sample to move along the capillary toward the detection electrode, thereby causing separation of the anions to occur; and d) detecting the anions indirectly using a UV/visible photometric detector.
Claim 2
Independent Claim 90 words
A method for detecting anions in a sample using capillary zone electrophoresis comprising the steps of: a) introducing the sample into a capillary; b) immersing the capillary in a carrier electrolyte containing a salt selected from the group consisting of molybdate, tungstate, ferrocyanide, ferricyanide, bromide, iodide and dichromate; c) applying an electrical current under conditions appropriate for the anions in the sample to move along the capillary toward the detection electrode, thereby causing separation of the anions to occur; and d) detecting the anions indirectly using a UV/visible photometric detector.
Claim 3
Dependent Claim 24 words
The method of claim 1 wherein the salt is a sodium salt having a concentration of from about 1.0 mM to about 20 mM.
Claim 4
Dependent Claim 17 words
The method of claim 1 wherein electrical voltage is from about 5 KV to about 40 KV.
Claim 5
Dependent Claim 14 words
The method of claim 1 wherein an electromigration additive is added to the sample.
Claim 6
Dependent Claim 26 words
The method of claim 4 wherein the electromigration additive is selected from the group consisting of an octanesulfonate salt, a carbonate salt and a citrate salt.
Claim 7
Dependent Claim 15 words
The method of claim 1 wherein the carrier electrolyte additionally contains an electroosmotic flow modifier.
Claim 8
Dependent Claim 26 words
The method of claim 6 wherein the electroosmotic flow modifier is selected from the group consisting of a cellulose, a glycol, a surfactant and a polyacrylamide.
Claim 9
Dependent Claim 22 words
The method of claim 7 wherein the electroosmotic flow modifier is selected from the group consisting of methylcellulose, hydroxypropylmethylcellulose and Tween 20.
Claim 10
Dependent Claim 23 words
The method of claim 6 wherein the electroosmotic flow modifier is selected from the group consisting of guanidine, diaminononane, di-n-butylamine and 3-N,N-dimethylpalmitylammonia propanesulfonate.
Claim 11
Dependent Claim 18 words
The method of claim 1 wherein the capillary has an electroosmotic flow modification to the capillary inner surface.
Claim 12
Dependent Claim 35 words
The method of claim 10 wherein the electroosmotic flow modification is a coating of the capillary inner surface with a substance selected from the group consisting of polyethylene glycol, polymethylsiloxane and polybutadiene maleic acid copolymer.
Claim 13
Independent Claim 104 words
A method for detecting anions in a sample using capillary zone electrophoresis comprising the steps of: a) introducing the sample into a capillary; b) immersing the capillary in a carrier electrolyte containing a chromate or vanadate salt and an electroosmotic flow modifier selected from the group consisting of a cellulose, a glycol, a surfactant, a polyacrylamide, guanidine, diaminononane, di-n-butylamine and 3-N,N-dimethylpalmitylammonia propanesulfonate; c) applying an electrical current under conditions appropriate for the anions in the sample to move along the capillary toward the detection electrode, thereby causing separation of the anions to occur; and d) detecting the anions indirectly using a UV/visible photometric detector.
Claim 14
Independent Claim 104 words
A method for detecting anions in a sample using capillary zone electrophoresis comprising the steps of: a) introducing the sample into a capillary; b) immersing the capillary in a carrier electrolyte containing a chromate or vanadate salt and an electroosmotic flow modifier selected from the group consisting of a cellulose, a glycol, a surfactant, a polyacrylamide, guanidine, diaminononane, di-n-butylamine and 3-N,N-dimethylpalmitylammonia propanesulfonate; c) applying an electrical current under conditions appropriate for the anions in the sample to move along the capillary toward the detection electrode, thereby causing separation of the anions to occur; and d) detecting the anions indirectly using a UV/visible photometric detector.
Claim 15
Independent Claim 101 words
A method for detecting anions in a sample using capillary zone electrophoresis comprising the steps of: a) introducing the sample into a capillary whose inner surface is coated with a substance selected from the group consisting of polyethylene glycol, polymethylsiloxane and polybutadiene maleic acid copolymer; b) immersing the capillary in a carrier electrolyte containing a chromate or vanadate salt; c) applying an electrical current under conditions appropriate for the anions in the sample to move along the capillary toward the detection electrode, thereby causing separation of the anions to occur; and d) detecting the anions indirectly using a UV/visible photometric detector.
Claim 16
Independent Claim 101 words
A method for detecting anions in a sample using capillary zone electrophoresis comprising the steps of: a) introducing the sample into a capillary whose inner surface is coated with a substance selected from the group consisting of polyethylene glycol, polymethylsiloxane and polybutadiene maleic acid copolymer; b) immersing the capillary in a carrier electrolyte containing a chromate or vanadate salt; c) applying an electrical current under conditions appropriate for the anions in the sample to move along the capillary toward the detection electrode, thereby causing separation of the anions to occur; and d) detecting the anions indirectly using a UV/visible photometric detector.

References Cited (Backward Citations)

US4414842A Cited
US4936974A Cited
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