US3915643A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Determination of salicylate
Assignee: Pierce Chemical Co
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Filing: 1974-08-08
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Granted: 1975-10-28
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Expires: 1994-08-08
Abstract
Abstract Salicylate content in blood serum or the like can be spectrophotometrically determined using a new reagent solution. The reagent solution contains ferric ions, tungstic acid, phosphoric acid and a polyoxyethylene/polyoxypropylene block copolymer which is an effectively non-ionic surfactant. Preferably, when human blood sera is used, the standard employed for calibration contains a base so that both the standard and the reagent solution containing unknown are at the same pH. The described technique has the advantages of the Trinder method but does not contain mercuric chloride.
Inventors
- 👤 E Melvin Gindler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:39
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/52; Y; Y10; Y10T; Y10T436/00; Y10T436/20; Y10T436/200833; Y10T436/201666
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
92 words
An aqueous reagent solution useful for the spectrophotometric determination of salicylate consisting essentially of ferric ions in excess of the amount necessary to combine with salicylate in the sample being analyzed, tungstic acid, phosphoric acid, and a water soluble polyoxyethylene/polyoxypropylene block copolymer as an effectively non-ionic surfactant, the tungstic acid being present in an amount sufficient to precipitate protein in the sample being analyzed with the phosphoric acid and non-ionic surfactant being present so as to provide a stable solution which, after removal of precipitated interfering proteins, is a clear, non-turbid liquid.
Claim 2
Dependent Claim
92 words
An aqueous reagent solution useful for the spectrophotometric determination of salicylate consisting essentially of ferric ions in excess of the amount necessary to combine with salicylate in the sample being analyzed, tungstic acid, phosphoric acid, and a water soluble polyoxyethylene/polyoxypropylene block copolymer as an effectively non-ionic surfactant, the tungstic acid being present in an amount sufficient to precipitate protein in the sample being analyzed with the phosphoric acid and non-ionic surfactant being present so as to provide a stable solution which, after removal of precipitated interfering proteins, is a clear, non-turbid liquid.
Claim 3
Dependent Claim
120 words
IN A SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF SALICYLATE COMPRISING ADDING A FERRIC CONTAINING REAGENT SOLUTION TO A SAMPLE TO BE ANALYZED PRECIPITATING INTERFERING PROTEINS AND THEREAFTER MEASURING THE INTENSITY OF THE FERRIC SALICYLATE COMPLEX THE IMPROVEMENT WHEREIN THE REAGENT SOLUTION CONSISTS ESSENTIALLY OF FERRIC IONS IN EXCESS OF THE AMOUNT NECESSARY TO COMBINE WITH SALICYLATE IN THE SAMPLE BEING ANALYZED TUNGSTIC ACID PHOSPHORIC ACID AND A WATER SOLUBLE POLYOXYETHYLENE/POLYOXYPROPYLENE BLOCK COPOLYMER EFFECTIVELY NON-IONIC SURFACTANT THE TUNGSTIC ACID BEING PRESENT IN AN AMOUNT SUFFICIENT TO PRECIPITATE PROTEIN IN THE SAMPLE BEING ANALYZED WITH THE PHOSPHORIC ACID AND NON-IONIC SURFACTANT BEING PRESENT SO AS TO PROVIDE A STABLE SOLUTION WHICH AFTER REMOVAL OF PRECIPITATED INTERFERING PROTEINS IS A CLEAR NONTURBID LIQUID.
Claim 4
Dependent Claim
120 words
IN A SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF SALICYLATE COMPRISING ADDING A FERRIC CONTAINING REAGENT SOLUTION TO A SAMPLE TO BE ANALYZED PRECIPITATING INTERFERING PROTEINS AND THEREAFTER MEASURING THE INTENSITY OF THE FERRIC SALICYLATE COMPLEX THE IMPROVEMENT WHEREIN THE REAGENT SOLUTION CONSISTS ESSENTIALLY OF FERRIC IONS IN EXCESS OF THE AMOUNT NECESSARY TO COMBINE WITH SALICYLATE IN THE SAMPLE BEING ANALYZED TUNGSTIC ACID PHOSPHORIC ACID AND A WATER SOLUBLE POLYOXYETHYLENE/POLYOXYPROPYLENE BLOCK COPOLYMER EFFECTIVELY NON-IONIC SURFACTANT THE TUNGSTIC ACID BEING PRESENT IN AN AMOUNT SUFFICIENT TO PRECIPITATE PROTEIN IN THE SAMPLE BEING ANALYZED WITH THE PHOSPHORIC ACID AND NON-IONIC SURFACTANT BEING PRESENT SO AS TO PROVIDE A STABLE SOLUTION WHICH AFTER REMOVAL OF PRECIPITATED INTERFERING PROTEINS IS A CLEAR NONTURBID LIQUID.
Claim 5
Dependent Claim
11 words
The solution of claim 1 wherein the surfactant has the structure
Claim 6
Dependent Claim
11 words
The method of claim 2 wherein the surfactant has the structure
Claim 7
Dependent Claim
25 words
The solution of claim 3 wherein the surfactant has a base molecular weight of 2501-3000 and a hydrophillic polyoxyethylene content, by weight of approximately 70%.
Claim 8
Dependent Claim
25 words
The method of claim 4 wherein the surfactant has a base molecular weight of 2501-3000 and a hydrophillic polyoxyethylene content, by weight of approximately 70%.
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) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |