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US4003706A
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Method and reagents for the detection, estimation and quantitative determination of nitrate ions
Assignee: Ben Gurion University of the Negev Research and Development Authority Ltd
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Filing: 1976-01-21
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Granted: 1977-01-18
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Expires: 1996-01-21
Abstract
Abstract Reagent and method for the detection, estimation and quantitative determiion of nitrate ions by mixing the reagents with aqueous nitrate samples, the intensity of the color reactions which result being proportional to the nitrate content of the samples which can be precisely measured by photometric measurements or estimated by comparison with color standards.
Inventors
- 👤 Eugen Szekely
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 01:47
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22; G01N31/227; Y; Y10; Y10T; Y10T436/00; Y10T436/17; Y10T436/173076
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
85 words
A method for the detection, estimation and quantitative determination of nitrate ions comprising preparing a nitrate reagent comprising: a. about 0.005 to 0.05 wt/v %. of a diphenylamine redox indicator; b. about 0.1 to 2.0 wt/v %. 4,4'-sulfonyldianiline; c. about 0.1 to 2.0 wt/v %. of a chloride selected from the group consisting of ammonium chloride, hydroxylamine hydrochloride or a mixture thereof; d. concentrated sulfuric acid; and e. concentrated phosphoric acid or an alkaline dihydrogen phosphate; and combining said reagent with an aqueous nitrate sample.
Claim 2
Independent Claim
85 words
A method for the detection, estimation and quantitative determination of nitrate ions comprising preparing a nitrate reagent comprising: a. about 0.005 to 0.05 wt/v %. of a diphenylamine redox indicator; b. about 0.1 to 2.0 wt/v %. 4,4'-sulfonyldianiline; c. about 0.1 to 2.0 wt/v %. of a chloride selected from the group consisting of ammonium chloride, hydroxylamine hydrochloride or a mixture thereof; d. concentrated sulfuric acid; and e. concentrated phosphoric acid or an alkaline dihydrogen phosphate; and combining said reagent with an aqueous nitrate sample.
Claim 3
Dependent Claim
32 words
The method of claim 1 wherein said diphenylamine redox indicator is selected from the group consisting of diphenylamine, diphenylbenzidine, diphenylamine sulfonic acid, diphenylbenzidine sulfonic acid and alkali or alkaline earth salts thereof.
Claim 4
Dependent Claim
25 words
A method according to claim 1 wherein in the determination procedure 1 volume of nitrate sample is mixed with at least 5 volumes of reagent.
Claim 5
Dependent Claim
25 words
A method according to claim 1 wherein in the determination procedure 1 volume of nitrate sample is mixed with at least 10 volumes of reagent.
Claim 6
Dependent Claim
16 words
A method according to claim 1 wherein the detection is performed by the spot test technique.
Claim 7
Dependent Claim
19 words
A method according to claim 1 wherein estimations and semiquantitative determinations are performed visually by comparison with color standards.
Claim 8
Dependent Claim
11 words
A method according to claim 1 wherein determinations are performed instrumentally.
Claim 9
Dependent Claim
16 words
A method according to claim 1 wherein quantitative determinations are performed by reading at 600 nm.
Claim 10
Dependent Claim
16 words
A method according to claim 1 wherein quantitative determinations are performed by reading at 570 nm.
Claim 11
Dependent Claim
29 words
A method according to claim 1 wherein the reagent constituents (a), (b) and (c) are prepared together in dry form and later combined with constituents (d), (e) for solubilization.
Claim 12
Dependent Claim
38 words
A method according to claim 1 wherein reagent constituent (e) is an alkaline dihydrogen phosphate and reagent constituents (a), (b), (c) and (e) are prepared together in dry form and constituent (d) is added during the estimation procedure.
Claim 13
Dependent Claim
74 words
A reagent for the detection, estimation and quantitative determination of nitrate ions upon combination with concentrated sulfuric acid and concentrated phosphoric acid or an alkaline dihydrogen phosphate comprising a. about 0.005 to 0.05 wt/v %. of a diphenylamine redox indicator; b. about 0.1 to 2 wt/v %. of 4,4'-sulfonyldianiline, and c. about 0.1 to 2.0 wt/v %. of a chloride selected from the group consisting of ammonium chloride, hydroxylamine hydrochloride or a mixture thereof.
Claim 14
Dependent Claim
74 words
A reagent for the detection, estimation and quantitative determination of nitrate ions upon combination with concentrated sulfuric acid and concentrated phosphoric acid or an alkaline dihydrogen phosphate comprising a. about 0.005 to 0.05 wt/v %. of a diphenylamine redox indicator; b. about 0.1 to 2 wt/v %. of 4,4'-sulfonyldianiline, and c. about 0.1 to 2.0 wt/v %. of a chloride selected from the group consisting of ammonium chloride, hydroxylamine hydrochloride or a mixture thereof.
Claim 15
Dependent Claim
68 words
A reagent for the detection and estimation of nitrate ions upon combination with concentrated sulfuric acid comprising: a. about 0.005 to 0.05 wt/v %. of a diphenylamine redox indicator; b. about 0.1 to 2 wt/v %. of 4,4'-sulfonyldianiline; c. about 0.1 to 2.0 wt/v %. of a chloride selected from the group consisting of ammonium chloride, hydroxylamine hydrochloride or a mixture thereof; and d. an alkaline dihydrogen phosphate.
Claim 16
Dependent Claim
68 words
A reagent for the detection and estimation of nitrate ions upon combination with concentrated sulfuric acid comprising: a. about 0.005 to 0.05 wt/v %. of a diphenylamine redox indicator; b. about 0.1 to 2 wt/v %. of 4,4'-sulfonyldianiline; c. about 0.1 to 2.0 wt/v %. of a chloride selected from the group consisting of ammonium chloride, hydroxylamine hydrochloride or a mixture thereof; and d. an alkaline dihydrogen phosphate.
Claim 17
Dependent Claim
71 words
A reagent for the detection, estimation and quantitative determination of nitrate ions comprising: a. about 0.005 to 0.05 wt/v %. of a diphenylamine redox indicator; b. about 0.1 to 2.0 wt/v %. 4,4'-sulfonyldianiline; c. about 0.1 to 2.0 wt/v %. of a chloride selected from the group consisting of ammonium chloride, hydroxylamine hydrochloride or a mixture thereof. d. concentrated sulfuric acid; and e. concentrated phosphoric acid or an alkaline dihydrogen phosphate.
Claim 18
Dependent Claim
71 words
A reagent for the detection, estimation and quantitative determination of nitrate ions comprising: a. about 0.005 to 0.05 wt/v %. of a diphenylamine redox indicator; b. about 0.1 to 2.0 wt/v %. 4,4'-sulfonyldianiline; c. about 0.1 to 2.0 wt/v %. of a chloride selected from the group consisting of ammonium chloride, hydroxylamine hydrochloride or a mixture thereof. d. concentrated sulfuric acid; and e. concentrated phosphoric acid or an alkaline dihydrogen phosphate.
Claim 19
Dependent Claim
34 words
A reagent according to claim 14 wherein said diphenylamine redox indicator is selected from the group consisting of diphenylamine, diphenylbenzidine, diphenylamine sulfonic acid, diphenyl benzidine sulfonic acid and alkali or alkaline earth salts thereof.
Claim 20
Dependent Claim
11 words
A reagent according to claim 14 wherein said indicator is diphenylamine.
Claim 21
Dependent Claim
12 words
A reagent according to claim 14 wherein said indicator is 4-diphenylamino-4-sulfonic acid.
Claim 22
Dependent Claim
14 words
A reagent according to claim 14 wherein said indicator is 4-diphenylamine-4-sulfonic acid sodium salt.
Claim 23
Dependent Claim
14 words
A reagent according to claim 14 wherein said indicator is 4-diphenylamine-4-sulfonic acid barium salt.
Claim 24
Dependent Claim
12 words
A reagent according to claim 14 wherein said indicator is diphenyl benzidine.
Claim 25
Dependent Claim
12 words
A reagent according to claim 14 wherein the chloride is ammonium chloride.
Claim 26
Dependent Claim
12 words
A reagent according to claim 14 wherein the chloride is hydroxylamine hydrochloride.
Claim 27
Dependent Claim
13 words
A reagent according to claim 14 wherein component e is concentrated phosphoric acid.
Claim 28
Dependent Claim
14 words
A reagent according to claim 14 wherein component e is an alkaline dihydrogen phosphate.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-01-18 | 1980-07-19 | 1981-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-18 | 1984-07-19 | 1985-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-18 | 1988-07-19 | 1989-01-18 | $7700.00 | Window Closed / Lapsed |