US3915831A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrogen sulfide sensing cell
Assignee: Thermo Orion Inc
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Filing: 1973-04-09
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Granted: 1975-10-28
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Expires: 1993-04-09
Abstract
Abstract An improved gas-sensing electrochemical cell for measuring dissolved hydrogen sulfide in a sample solution. The cell comprises a potentiometric sulfide ion-sensitive electrode and a fluoride ion-sensitive electrode, both in contact with an acid internal standard solution comprising an aqueous solution of a fluoride salt. A hydrophobic hydrogen sulfide gas-permeable membrane separates the sample solution from the internal solution.
Inventors
- 👤 John H Riseman
- 👤 Martin S Frant
- 👤 John A Krueger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:33
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/28; G01N27/30; G01N27/333; G01N27/3335
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
115 words
AN ELECTROCHEMICAL CELL FOR MEASURING THE HYDROGEN SULFIDE CONTENT OF A SAMPLE SOLUTION, SAID CELL COMPRISING IN COMBINATION A POTENTIOMETRIC SULFIDE ION-SENSITIVE MEMBRANCE ELECTRODE FOR PROVIDING AN ELECTROCHEMICAL POTENTIAL RESPONSIVELY TO THE ACTIVITY OF SULFIDE ION IN SOLUTION, A BODY OF ELECTROLYTE OF FIXED PH IN THE RANGE BETWEEN ABOUT PH 4 TO 7 IN CONTACT WITH THE ION-SENSITIVE PORTION OF SAID SULFIDE SENSITIVE ELECTRODE AND CONTAINING FLUORIDE IONS IN A SUBSTANTIALLY FIXED CONCENTRATION, A POTENTIOMETRIC FLUORIDE ION-SENSITIVE MEMBRANE ELECTRODE IN CONTACT WITH SAID ELECTROLYTE FOR PROVIDING A SUBSTANTIALLY FIXED POTENTIAL WITH RESPECT TO SAID ELECTROLYTE: AND A HYDROGEN SULFIDE PERMEABLE MEMBRANE ARRANGED SO AS TO SEPERATE THE ELECTRODES AND ELECTROLYTE FROM SAID SAMPLE SOLUTION.
Claim 2
Dependent Claim
115 words
AN ELECTROCHEMICAL CELL FOR MEASURING THE HYDROGEN SULFIDE CONTENT OF A SAMPLE SOLUTION, SAID CELL COMPRISING IN COMBINATION A POTENTIOMETRIC SULFIDE ION-SENSITIVE MEMBRANCE ELECTRODE FOR PROVIDING AN ELECTROCHEMICAL POTENTIAL RESPONSIVELY TO THE ACTIVITY OF SULFIDE ION IN SOLUTION, A BODY OF ELECTROLYTE OF FIXED PH IN THE RANGE BETWEEN ABOUT PH 4 TO 7 IN CONTACT WITH THE ION-SENSITIVE PORTION OF SAID SULFIDE SENSITIVE ELECTRODE AND CONTAINING FLUORIDE IONS IN A SUBSTANTIALLY FIXED CONCENTRATION, A POTENTIOMETRIC FLUORIDE ION-SENSITIVE MEMBRANE ELECTRODE IN CONTACT WITH SAID ELECTROLYTE FOR PROVIDING A SUBSTANTIALLY FIXED POTENTIAL WITH RESPECT TO SAID ELECTROLYTE: AND A HYDROGEN SULFIDE PERMEABLE MEMBRANE ARRANGED SO AS TO SEPERATE THE ELECTRODES AND ELECTROLYTE FROM SAID SAMPLE SOLUTION.
Claim 3
Dependent Claim
17 words
An electrochemical cell as defined in claim 1 wherein said electrolyte contains an antioxidant for sulfide ions.
Claim 4
Dependent Claim
14 words
An electrochemical cell as defined in claim 2 wherein said antioxidant is ascorbic acid.
Claim 5
Dependent Claim
45 words
An improved gas-sensing electrochemical cell as defined in claim 1 wherein the said sulfide sensitive electrode has, as the ion-sensitive portion thereof a membrane of substantially pure Ag2S which is substantially free of silver on at least the surface thereof intended to contact said electrolyte.
Claim 6
Dependent Claim
24 words
An electrochemical cell as defined in claim 1 wherein the ion sensitive portion of said reference electrode is a membrane of crystalline lanthanum fluoride.
Claim 7
Dependent Claim
18 words
An electrochemical cell as defined in claim 1 wherein the pH of said electrolyte is substantially around 5.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |