US4042464A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the detection and measurement of noxious gases
Assignee: Becton Dickinson and Co
•
Filing: 1975-10-10
•
Granted: 1977-08-16
•
Expires: 1995-10-10
Abstract
Abstract Noxious gases are electrochemically detected and measured in the presence of carbon monoxide using a device employing an electrochemical cell whose sensing electrode comprises a carbon supported gold catalyst and is maintained at a fixed potential of about 0.4 volt to about 1.5 volt with respect to a reversible hydrogen electrode in said electrolyte of the electrochemical cell. In its preferred form the sensing electrode comprises carbon particles containing catalytic amounts of gold bonded to a hydrophobic material to provide a diffusion electrode.
Inventors
- 👤 Keith F. Blurton
- 👤 John M. Sedlak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:18
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/404; G01N27/4045
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
138 words
A method for electrochemically detecting a noxious gas selected from the group consisting of nitric oxide, nitrogen dioxide, sulfur dioxide, mercaptans and hydrogen sulfide in the presence of carbon monoxide which comprises the steps of (1) feeding a gaseous sample containing said gas to the sensing electrode of an electrochemical cell comprising a sensing electrode, a counterelectrode, and an aqueous electrolyte in contact with said sensing electrode and counterelectrode, said sensing electrode comprising a carbon supported gold catalyst; (2) maintaining said sensing electrode at a fixed potential of about 0.4 volt to 1.5 volts with respect to the potential of the reversible hydrogen couple in the electrolyte of said cell; and (3) measuring the current flowing between said sensing electrode and counterelectrode of said cell to quantitatively determine the amount of said noxious gas in said gaseous sample.
Claim 2
Independent Claim
138 words
A method for electrochemically detecting a noxious gas selected from the group consisting of nitric oxide, nitrogen dioxide, sulfur dioxide, mercaptans and hydrogen sulfide in the presence of carbon monoxide which comprises the steps of (1) feeding a gaseous sample containing said gas to the sensing electrode of an electrochemical cell comprising a sensing electrode, a counterelectrode, and an aqueous electrolyte in contact with said sensing electrode and counterelectrode, said sensing electrode comprising a carbon supported gold catalyst; (2) maintaining said sensing electrode at a fixed potential of about 0.4 volt to 1.5 volts with respect to the potential of the reversible hydrogen couple in the electrolyte of said cell; and (3) measuring the current flowing between said sensing electrode and counterelectrode of said cell to quantitatively determine the amount of said noxious gas in said gaseous sample.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein the carbon supported gold catalyst particles are bonded to a hydrophobic material to provide a diffusion electrode.
Claim 4
Dependent Claim
11 words
The method of claim 2 wherein the hydrophobic material is polytetrafluoroethylene.
Claim 5
Dependent Claim
20 words
The method of claim 1 wherein the electrochemical cell further comprises, a reference electrode at which substantially no current flows.
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) | 1980-08-15 | 1981-02-14 | 1981-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-15 | 1985-02-14 | 1985-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-15 | 1989-02-14 | 1989-08-16 | $7700.00 | Window Closed / Lapsed |