US4105408A
Expired / Lapsed
US
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Urea assay
Assignee: INDIANA DEVELOPMENT FINANCE AUTHORITY
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Filing: 1977-10-13
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Granted: 1978-08-08
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Expires: 1997-10-13
Abstract
Abstract A 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 07:10
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: 4
Claim 1
Independent Claim
77 words
A process for the quantitation of urea in a fluid sample, in which the sample is reacted with a reagent containing an acidic solution of o-phthalaldehyde and an acidic solution of a chromogenic compound of the general class consisting of 1, or 1,3-mono- or di-substituted hydroxy or methoxy naphthalene compounds which have the following general formula: ##STR7## where R 1 = --H, or --CH 3 and where R 2 = --H, or --OH, or --OCH 3 .
Claim 2
Dependent Claim
77 words
A process for the quantitation of urea in a fluid sample, in which the sample is reacted with a reagent containing an acidic solution of o-phthalaldehyde and an acidic solution of a chromogenic compound of the general class consisting of 1, or 1,3-mono- or di-substituted hydroxy or methoxy naphthalene compounds which have the following general formula: ##STR7## where R 1 = --H, or --CH 3 and where R 2 = --H, or --OH, or --OCH 3 .
Claim 3
Dependent Claim
15 words
The process as defined in claim 1, in which the chromogenic compound used is 1,3-dihydroxynaphthalene.
Claim 4
Dependent Claim
15 words
The process as defined in claim 1, in which the chromogenic compound used is 1-hydroxynaphthalene.
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) | 1981-08-07 | 1982-02-06 | 1982-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-07 | 1986-02-06 | 1986-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-07 | 1990-02-06 | 1990-08-08 | $7700.00 | Window Closed / Lapsed |