US5156724A
Expired / Lapsed
US
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Method for analyzing ionic species using capillary electrophoresis
Assignee: Waters Technologies Corp
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Filing: 1991-01-17
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Granted: 1992-10-20
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Expires: 2011-01-17
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 15:20
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/447; G01N27/44704; G01N27/44717; G01N27/44721
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
89 words
A method for detecting cations in a sample using capillary zone electrophoresis comprising the steps of: a. introducing the sample into a capillary; b. immersing the capillary into a carrier electrolyte consisting essentially of a UV-absorbing amine or heterocyclic sulfonate compound of similar mobility as the analyzed cation; c. applying an electrical current under conditions appropriate for the cations in the sample to move along the capillary toward the anode, thereby causing separation of the cations to occur; and d. detecting the cations indirectly using a UV/visible photometric detector.
Claim 2
Independent Claim
89 words
A method for detecting cations in a sample using capillary zone electrophoresis comprising the steps of: a. introducing the sample into a capillary; b. immersing the capillary into a carrier electrolyte consisting essentially of a UV-absorbing amine or heterocyclic sulfonate compound of similar mobility as the analyzed cation; c. applying an electrical current under conditions appropriate for the cations in the sample to move along the capillary toward the anode, thereby causing separation of the cations to occur; and d. detecting the cations indirectly using a UV/visible photometric detector.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein the UV-absorbing amine is 4-methylbenzylamine having a concentration of from about 3 mM to about 10 mM.
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein a chelating agent is added to the carrier electrolyte.
Claim 5
Dependent Claim
22 words
The method of claim 3 wherein the chelating agent is selected from the group consisting of citrate, succinate, tartrate, hydroxyisobutyrate, and oxalate.
Claim 6
Dependent Claim
17 words
The method of claim 1 wherein the electrical voltage is from about 5 to about 40 kV.
Claim 7
Dependent Claim
11 words
The method of claim 1 wherein the cations are inorganic cations.
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) | 1995-10-20 | 1996-04-20 | 1996-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-20 | 2000-04-20 | 2000-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-20 | 2004-04-20 | 2004-10-20 | $7700.00 | Window Closed / Lapsed |