US5128005A
Expired / Lapsed
US
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Method for separating ionic species using capillary electrophoresis
Assignee: Waters Technologies Corp
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Filing: 1991-11-25
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Granted: 1992-07-07
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Expires: 2011-11-25
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 and cationic species. The method involves introducing a sample containing the ionic species into a narrow core capillary filled with a carrier electrolyte containing a selected light-absorbing anion or cation to an electrical current in a 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
- 👤 Michael Merion
- 👤 Andrea Weston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:23
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/447; G01N27/44704; G01N27/44717; G01N27/44721
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
76 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 salt; c. applying an electrical current under conditions appropriate for the anions in the sample to move along the capillary toward the anode thereby causing separation of the anions to occur; and d. detecting the anions indirectly using a UV/visible photometric detector.
Claim 2
Independent Claim
76 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 salt; c. applying an electrical current under conditions appropriate for the anions in the sample to move along the capillary toward the anode 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 chromate salt is sodium chromate having a concentration of from about 1.0 mM to about 20 mM.
Claim 4
Dependent Claim
34 words
The method of claim 1 wherein an alkyl quaternary ammonium salt, arsonium salt or phosphonium salt containing at least one alkyl group having more than eight carbon atoms is added to the carrier electrolyte.
Claim 5
Dependent Claim
25 words
The method of claim 3 wherein the alkyl quaternary salt is tetradecyltrimethylammonium bromide having a concentration of from about 0.1 mM to about 5.0 mM.
Claim 6
Dependent Claim
26 words
The method of claim 3 wherein the alkyl quaternary salt is cetyltrimethyl ammonium bromide having a concentration of from about 0.1 mM to about 5.0 mM.
Claim 7
Dependent Claim
20 words
The method of claim 1 wherein the alkyl quaternary ammonium, arsonium or phosphonium salt is immobilized on the capillary wall.
Claim 8
Dependent Claim
16 words
The method of claim 1 wherein electrical voltage is from about 5 to about 40 KV.
Claim 9
Dependent Claim
14 words
The method of claim 1 wherein an electromigration additive is added to the sample.
Claim 10
Dependent Claim
25 words
The method of claim 8 wherein the electromigration additive is selected from the group of: an octanesulfonate salt, a carbonate salt and a citrate salt.
Claim 11
Dependent Claim
12 words
The method of claim 9 wherein the electromigration additive is sodium octanesulfonate.
Claim 12
Dependent Claim
29 words
The method of claim 1 wherein the anions are complex organic anions selected from the group consisting of: anionic complexes of metals, carboxylic acids, sulfonic acids and alkyl sulfates.
Claim 13
Dependent Claim
11 words
The method of claim 1 wherein the anions are inorganic anions.
Claim 14
Dependent Claim
17 words
The method of claim 1 wherein a vanadate salt is used in lieu of the chromate salt.
References Cited (Backward Citations)
US4414842A
Cited
US4936974A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-07-07 | 1996-01-06 | 1996-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-07-07 | 2000-01-06 | 2000-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-07-07 | 2004-01-06 | 2004-07-07 | $7700.00 | Window Closed / Lapsed |