US3650696A
Expired / Lapsed
US
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Sampling and analysis of sulfur compounds
Assignee: Lamar State College of Technology
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Filing: 1970-09-08
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Granted: 1972-03-21
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Expires: 1990-09-08
Abstract
Abstract A method for accurately sampling ambient air containing sulfur compounds in the low parts per billion range and for separating, identifying and quantitatively monitoring each sulfur compound. The gaseous sample is collected in substantially sulfur-free methanol. The methanol solution is then passed through a gas chromatograph column packed with octylphenoxypolyethylene on oxyethanol polytetrafluoroethylene to separate the sulfur compounds. From the gas chromatograph the separated sulfur compounds go through a pyrolysis furnace where they are oxidized to sulfur dioxide, and thence into a microcoulometer for titration. By using the same procedure, sulfur compound impurities in solid materials can be identified and quantitatively measured.
Inventors
- 👤 Ewin A Eads
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:02
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/0004; G01N33/0009; G01N33/0027; G01N33/0036; G01N33/0047; G01N31/00; G01N31/16; G01N33/0044; Y; Y02; Y02A; Y02A50/00; Y02A50/20; Y10; Y10T; Y10T436/00; Y10T436/14; Y10T436/145555; Y10T436/18; Y10T436/188
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
22 words
The method according to claim 1 wherein said gaseous mixture is ambient air containing parts per billion concentrations of odor-causing sulfur compounds.
Claim 2
Independent Claim
113 words
The method of sampling and analyzing a gaseous mixture containing low concentrations of sulfur compounds comprising the successive steps of: a. passing a measured amount of said gaseous mixture through substantially sulfur-free methanol to absorb essentially all the said sulfur compounds in the methanol; b. passing the methanol containing the absorbed sulfur compounds through a gas chromatograph column essentially inert to methanol and sulfur compounds in methanol to separate the sulfur compounds; c. oxidizing the sulfur compounds as separated to form sulfur dioxide; and d. titrating the separated, oxidized sulfur compounds in the form of sulfur dioxide in a microcoulometer to thereby determine the concentration of each sulfur compound in the gaseous mixture.
Claim 3
Dependent Claim
22 words
The method according to claim 3 wherein the gaseous mixture is ambient air containing parts per billion concentrations of odor-causing sulfur compounds.
Claim 4
Dependent Claim
26 words
The method according to claim 3 wherein the separated, oxidized sulfur compounds in the form of sulfur dioxide are titrated with iodide ions in a microcoulometer.
Claim 5
Dependent Claim
30 words
The method according to claim 5 wherein the sulfur compounds as separated are oxidized at a temperature in the range from about 675*C. to about 725*C. to form sulfur dioxide.
Claim 6
Independent Claim
115 words
The method of sampling, separating and quantitatively measuring low concentrations of sulfur compounds in a gaseous mixture comprising the successive steps of: a. passing a measured amount of said gaseous mixture through substantially sulfur-free methanol to absorb essentially all the said sulfur compounds in the methanol; b. passing the methanol containing the absorbed sulfur compounds through a gas chromatograph column packed with octylphenoxypolyethylene oxyethanol on polytetrafluoroethylene to separate the sulfur compounds; c. oxidizing the sulfur compounds as separated to form sulfur dioxide; and d. titrating the separated, oxidized sulfur compounds in the form of sulfur dioxide with iodide ions in a microcoulometer to thereby determine the concentration of each sulfur compound in the gaseous mixture.
Claim 7
Dependent Claim
46 words
The method according to claim 7 wherein the gaseous mixture is ambient air containing parts per billion concentrations of odor-causing sulfur compounds, and the sulfur compounds as separated are oxidized at a temperature in the range from about 675*C. to about 725*C. to form sulfur dioxide.
Claim 8
Dependent Claim
59 words
The method according to claim 8 wherein the sulfur compounds are heterocyclic sulfur compounds; the heterocyclic sulfur compounds as separated are oxidized at a temperature in the range from about 675*C. to about 725*C. to form sulfur dioxide; and the separated, oxidized heterocyclic sulfur compounds in the form of sulfur dioxide are titrated with iodide ions in a microcoulometer.
Claim 9
Independent Claim
113 words
The method of sampling and analyzing a solid material containing low concentrations of sulfur compounds comprising the successive steps of: a. dissolving a measured amount of said solid material in substantially sulfur-free methanol to absorb essentially all the said sulfur compounds in the methanol; b. passing the methanol containing the absorbed sulfur compounds through a gas chromatograph column essentially inert to methanol and sulfur compounds in methanol to separate the sulfur compounds; c. oxidizing said sulfur compounds as separated to form sulfur dioxide; and d. titrating the separated, oxidized sulfur compounds in the form of sulfur dioxide in a microcoulometer to thereby determine the concentration of each sulfur compound in said solid material.
References Cited (Backward Citations)
US3529937A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-21 | 1975-09-20 | 1976-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-21 | 1979-09-20 | 1980-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-21 | 1983-09-20 | 1984-03-21 | $7700.00 | Window Closed / Lapsed |