US3816075A
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US
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Determination of hypophosphite ion concentration
Assignee: United States Atomic Energy Commission
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Filing: 1972-11-28
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Granted: 1974-06-11
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Expires: 1992-11-28
Abstract
Abstract A sample solution containing hypophosphite and phosphite ions is acidified a sufficient amount to convert most of the phosphite ions to an unreactive form. A solution of ferric ions is combined with the sample and the mixture heated to oxidize the hypophosphite while reducing the ferric to ferrous ions. A complexing agent and a pH buffer are included in the mixture to produce a red colored ferrous complex from which the original concentration of the hypophosphite ion is photometrically determined.
Inventors
- 👤 M Lambert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:13
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22; G01N31/02; Y; Y10; Y10T; Y10T436/00; Y10T436/16; Y10T436/25; Y10T436/25625
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
110 words
The method of claim 1 wherein a flow of sample solution is diluted by a volumetric factor of about 10 to 12 to form a first diluted solution flow, a fraction of said first diluted solution flow is separated and further diluted to a volumetric factor of about 70 to 80 per original part of solution prior to said heating step to form a second diluted solution flow, and a fraction of said second diluted solution flow is separated subsequent to said heating step and diluted to a volumetric factor of about 900 to 1,100 per original part of solution prior to photometrically determining the concentration of said ferrous ions.
Claim 2
Dependent Claim
53 words
The method of claim 2 wherein said second diluted solution flow is prepared with a hydrogen ion concentration of about 0.3 to 0.8 mole per liter by combining flows of hydrochloric acid and ferric ion solutions and subsequently intermixing the combined flow with the separated fraction of said first diluted sample solution flow.
Claim 3
Dependent Claim
47 words
The method of claim 1 wherein said ferrous ions are photometrically determined by adding a chemical complexing reagent to form a ferrous ion complex having a known peak of light absorbance at a particular wavelength and thereafter measuring the light absorbance within said solution at said wavelength.
Claim 4
Dependent Claim
11 words
The method of claim 4 wherein said complexing reagent is ortho-phenanthroline.
Claim 5
Dependent Claim
23 words
The method of claim 5 wherein said photometric determination is performed while maintaining said solution with ortho-phenanthroline at a pH of about 4.8.
Claim 6
Dependent Claim
27 words
The method of claim 5 wherein said photometric determination is performed by measuring the absorbance of a monochromatic light beam having a wavelength of about 510 nm.
Claim 7
Dependent Claim
27 words
The method of claim 1 wherein said ferric ions are added in a stoichiometric ratio of about 5 to 1 in respect to said hypophosphite ion concentration.
Claim 8
Dependent Claim
34 words
The method of claim 1 wherein said solution is heated to a temperature of about 90*C. and maintained at said temperature for about 5 to 10 minutes during the oxidation of said hypophosphite ions.
Claim 9
Dependent Claim
25 words
The method of claim 1 wherein thallium ions are added to said solution prior to said heating step to catalyze said oxidation of hypophosphite ioNs.
References Cited (Backward Citations)
US2697651A
Cited
US3425805A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |