Patent US3874853A successfully refreshed from Google Patents.
US3874853A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for determining the concentration of inorganic phosphates in human fluids
Assignee: Damon Corp
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Filing: 1972-11-16
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Granted: 1975-04-01
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Expires: 1992-11-16
Abstract
Abstract In a testing procedure for determining the concentration of a organic phosphate in human fluids by determining the amount of light absorbance of a chromogen in a test sample formed by reacting the phosphate with at least two reagents in two separate steps, a true blank is prepared having a light absorbance representative of all the constituents in the sample other than the chromogen. The true blank is prepared by adding the same reagents to a blank sample in a sequence different from that used for the test sample so that the conditions under which the chromogen is formed are avoided in the blank sample.
Inventors
- 👤 Ronald K Byrnes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:29
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/84; Y; Y10; Y10T; Y10T436/00; Y10T436/16; Y10T436/166666
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
173 words
IN A PROCESS FOR DETERMINING THE CONCENTRATION OF INORGANIC PHOSPHATE IN HUMAN FLUIDS WHEREIN A TEST SAMPLE OF A HUMAN FLUID IS TREATED WITH AN ACIDIC AQUEOUS SOLUTION OF AMMONIUM MOLYBDATE TO FORM A REDUCABLE PHOSPHOMOLYBDATE COMPLEX IN A FIRST STEP AND REACTING SAID COMPLEX WITH A BASIC AQUEOUS SOLUTION OF A REDUCING AGENT TO FORM A REACTION PRODUCT CAPABLE OF ABSORBING ELECTROMAGNETIC RADIATION IN ACCORDANCE WITH BEER''S LAW AND WHEREIN THE ELECTROMAGNETIC RADIATION ABSORBANCE OF SAID REACTION PRODUCT IS MEASURED, THE IMPROVEMENT WHICH COMPRISES FORMING A BLANK SAMPLE OF SAID HUMAN FLUID BY ADMIXING SAID HUMAN FLUID IN A CONTAINER SEPARATE FROM SAID TEST SAMPLE FIRST WITH THE BASIC AQUEOUS SOLUTION AND THEREAFTER WITH ALL THE OTHER REAGENTS ADDED TO THE TEST SAMPLE UNDER CONDITIONS SUCH THAT THE FINAL BLANK SAMPLE HAS A PH HIGHER THAN THAT AT WHICH THE PHOSPHOMOLYBDATE IS FORMED WHILE RETAINING ALL REAGENTS IN SOLUTION AND COMPARING THE ELECTROMAGNETIC RADIATION ABSORBANCE OF THE BLANK SAMPLE WITH THE ELECTROMAGNETIC RADIATION ABSORBANCE OF SAID REACTION PRODUCT IN THE TEST SAMPLE.
Claim 2
Dependent Claim
173 words
IN A PROCESS FOR DETERMINING THE CONCENTRATION OF INORGANIC PHOSPHATE IN HUMAN FLUIDS WHEREIN A TEST SAMPLE OF A HUMAN FLUID IS TREATED WITH AN ACIDIC AQUEOUS SOLUTION OF AMMONIUM MOLYBDATE TO FORM A REDUCABLE PHOSPHOMOLYBDATE COMPLEX IN A FIRST STEP AND REACTING SAID COMPLEX WITH A BASIC AQUEOUS SOLUTION OF A REDUCING AGENT TO FORM A REACTION PRODUCT CAPABLE OF ABSORBING ELECTROMAGNETIC RADIATION IN ACCORDANCE WITH BEER''S LAW AND WHEREIN THE ELECTROMAGNETIC RADIATION ABSORBANCE OF SAID REACTION PRODUCT IS MEASURED, THE IMPROVEMENT WHICH COMPRISES FORMING A BLANK SAMPLE OF SAID HUMAN FLUID BY ADMIXING SAID HUMAN FLUID IN A CONTAINER SEPARATE FROM SAID TEST SAMPLE FIRST WITH THE BASIC AQUEOUS SOLUTION AND THEREAFTER WITH ALL THE OTHER REAGENTS ADDED TO THE TEST SAMPLE UNDER CONDITIONS SUCH THAT THE FINAL BLANK SAMPLE HAS A PH HIGHER THAN THAT AT WHICH THE PHOSPHOMOLYBDATE IS FORMED WHILE RETAINING ALL REAGENTS IN SOLUTION AND COMPARING THE ELECTROMAGNETIC RADIATION ABSORBANCE OF THE BLANK SAMPLE WITH THE ELECTROMAGNETIC RADIATION ABSORBANCE OF SAID REACTION PRODUCT IN THE TEST SAMPLE.
Claim 3
Dependent Claim
19 words
The process of claim 1 wherein the basic reagent contains polyvinylpyrrolidone having an average molecular weight less than 40,000.
Claim 4
Dependent Claim
11 words
The process of claim 1 wherein the reducing agent comprises dipyrone.
Claim 5
Dependent Claim
19 words
The process of claim 3 wherein the basic reagent contains polyvinylpyrrolidone having an average molecular weight less than 40,000.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |