Patent US3973911A successfully refreshed from Google Patents.
US3973911A
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Sulfur oxide determination
Assignee: University of Illinois Foundation
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Filing: 1975-02-06
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Granted: 1976-08-10
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Expires: 1995-02-06
Abstract
Abstract Disclosed are systems, methods and materials for use in detection and quantification of sulfur oxides in a fluid sample. Involved is the reaction of a selected compound which is substantially non-fluorescent under given reaction conditions, e.g., 5-amino-3-sulfo-salicylic acid in a pH 1-3 solution, with sulfur oxides in the fluid sample to form a fluorescent reaction product which may be quantified by standard fluorometric techniques.
Inventors
- 👤 Alfred VON Smolinski
- 👤 Kuo-Chuan Feng
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 16:33
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N21/6428; G01N21/643; Y; Y10; Y10T; Y10T436/00; Y10T436/18; Y10T436/186
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
42 words
A reagent suitable for use in quantitatively determining the sulfur oxide content of a fluid sample, said reagent essentially consisting of: an aqueous solution of an acid and 5-amino-3-sulfo-salicylic acid, said solution having a pH of from about 1 to about 3.
Claim 2
Dependent Claim
42 words
A reagent suitable for use in quantitatively determining the sulfur oxide content of a fluid sample, said reagent essentially consisting of: an aqueous solution of an acid and 5-amino-3-sulfo-salicylic acid, said solution having a pH of from about 1 to about 3.
Claim 3
Dependent Claim
10 words
A reagent according to claim 1 further including an aldehyde.
Claim 4
Dependent Claim
11 words
A reagent according to claim 2 wherein said aldehyde is formaldehyde.
Claim 5
Dependent Claim
15 words
A reagent according to claim 1 wherein the pH of said solution is about 1.7.
Claim 6
Dependent Claim
12 words
A reagent according to claim 1 wherein said acid comprises phosphoric acid.
Claim 7
Independent Claim
59 words
A method for quantitatively determining the sulfur oxide content of a fluid sample, said method comprising: forming an aqueous reaction mixture essentially consisting of said fluid sample, an acid, an aldehyde and 5-amino-3-sulfo-salicylic acid, said reaction mixture having a pH of about 1 to about 3; and quantitatively analyzing said reaction mixture for the presence of fluorescent materials therein.
Claim 8
Independent Claim
59 words
A method for quantitatively determining the sulfur oxide content of a fluid sample, said method comprising: forming an aqueous reaction mixture essentially consisting of said fluid sample, an acid, an aldehyde and 5-amino-3-sulfo-salicylic acid, said reaction mixture having a pH of about 1 to about 3; and quantitatively analyzing said reaction mixture for the presence of fluorescent materials therein.
Claim 9
Dependent Claim
10 words
The method of claim 6 wherein said aldehyde is formaldehyde.
Claim 10
Dependent Claim
15 words
The method of claim 6 wherein said reaction mixture has a pH of about 1.7.
Claim 11
Dependent Claim
11 words
The method of claim 6 wherein said acid comprises phosphoric acid.
Claim 12
Dependent Claim
43 words
The method of claim 6 wherein said quantitative analysis step includes subjecting said reaction mixture to excitation by light having a wavelength of about 375 nm and thereafter monitoring said reaction mixture for emission of light having a wavelength of about 480 nm.
Claim 13
Dependent Claim
66 words
The method of claim 6 further including comparing the results of said quantitative analysis step to the results of the quantitative analysis for fluorescent materials in a separately prepared aqueous reaction mixture essentially consisting of an acid, an aldehyde, 5-amino-3-sulfo-salicylic acid and a fluid sample containing a known quantity of sulfur oxide, said separate reaction mixture having a pH of from about 1 to about 3.
Claim 14
Dependent Claim
76 words
Apparatus for the direct fluorometric determination of the sulfur oxide content of a fluid sample, said apparatus comprising: fluid container means transparent to light of a wavelength of from about 375 to about 480 nm; separate means for introducing a fluid reagent and a fluid sample containing sulfur dioxide into said container, wherein they react; means for monitoring the emission of light, having a wavelength of about 480 nm, from a fluid within said container means.
Claim 15
Dependent Claim
76 words
Apparatus for the direct fluorometric determination of the sulfur oxide content of a fluid sample, said apparatus comprising: fluid container means transparent to light of a wavelength of from about 375 to about 480 nm; separate means for introducing a fluid reagent and a fluid sample containing sulfur dioxide into said container, wherein they react; means for monitoring the emission of light, having a wavelength of about 480 nm, from a fluid within said container means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-10 | 1980-02-09 | 1980-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-10 | 1984-02-09 | 1984-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-10 | 1988-02-09 | 1988-08-10 | $7700.00 | Window Closed / Lapsed |