Patent US4131430A successfully refreshed from Google Patents.
US4131430A
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Urea assay
Assignee: INDIANA DEVELOPMENT FINANCE AUTHORITY
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Filing: 1978-03-13
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Granted: 1978-12-26
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Expires: 1998-03-13
Abstract
Abstract Urea assay or analysis process and reagents therefor, in which the assay involves a reaction between a sample of biological fluid and an acidic reagent solution of o-phthaldehyde and a chromogenic compound; the chromogenic compounds include certain substituted benzene compounds, certain substituted naphthalene compounds, certain aminopyrimidines, certain substituted quinolines, certain morpholino substituted quinolines and certain morpholino substituted naphthalenes.
Inventors
- 👤 Jerry W. Denney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:20
CPC Classifications
C; C07; C07D; C07D215/00; C07D215/02; C07D215/16; C07D215/38; C07D215/42; C07D215/46; G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/62; Y; Y10; Y10T; Y10T436/00; Y10T436/17; Y10T436/171538
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
90 words
A process for the quantitation of urea in a fluid sample, comprising reacting the sample with a reagent containing an acidic solution of o-phthaladehyde and an acidic solution of a chromogenic compound of the general class of compounds which have the following general structure: ##STR7## where R 1 = -H, --OCH, or --OH and where R 2 = -H, --CH 3 or --C 2 H 5 and where X = O or C and where n = 1, 2 or 3 and measuring the absorbance of the reacted sample mixture.
Claim 2
Dependent Claim
90 words
A process for the quantitation of urea in a fluid sample, comprising reacting the sample with a reagent containing an acidic solution of o-phthaladehyde and an acidic solution of a chromogenic compound of the general class of compounds which have the following general structure: ##STR7## where R 1 = -H, --OCH, or --OH and where R 2 = -H, --CH 3 or --C 2 H 5 and where X = O or C and where n = 1, 2 or 3 and measuring the absorbance of the reacted sample mixture.
Claim 3
Dependent Claim
15 words
The process as defined in claim 1, in which the chromogenic compound used is 2-N-morpholinoethyl-1-naphthylamine.
References Cited (Backward Citations)
US3890099A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-12-25 | 1982-06-26 | 1982-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-25 | 1986-06-26 | 1986-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-25 | 1990-06-26 | 1990-12-26 | $7700.00 | Window Closed / Lapsed |