US4131425A
Expired / Lapsed
US
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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 17:50
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: 5
Claim 1
Independent Claim
86 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-phthalaldehyde and an acidic solution of a chromogenic compound of the general class of compounds consisting of 1,3 or 1,3,5 di- or tri-substituted hydroxy or methoxy benzene compounds, which have the following general structure: ##STR7## where R 1 = --H, or --CH 3 and where R 2 = --H, or --OH, or --OCH 3 and measuring the absorbance of the reacted sample mixture.
Claim 2
Dependent Claim
86 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-phthalaldehyde and an acidic solution of a chromogenic compound of the general class of compounds consisting of 1,3 or 1,3,5 di- or tri-substituted hydroxy or methoxy benzene compounds, which have the following general structure: ##STR7## where R 1 = --H, or --CH 3 and where R 2 = --H, or --OH, or --OCH 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 1,3-dihydroxybenzene.
Claim 4
Dependent Claim
15 words
The process as defined in claim 1, in which the chromogenic compound used is 1,3,5-trihydroxybenzene.
Claim 5
Dependent Claim
15 words
The process as defined in claim 1, in which the chromogenic compound used is 1,3-dimethoxybenzene.
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 |