US3975155A
Expired / Lapsed
US
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Quantitative method for detecting 3-isothiazolones
Assignee: Rohm and Haas Co
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Filing: 1975-06-04
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Granted: 1976-08-17
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Expires: 1995-06-04
Abstract
Abstract Quantitative analytical method for the isolation and determination of 3-isothiazolones in aqueous or nonaqueous media. The method involves isolating the isothiazolone by adsorbing it on a support; treating the isothiazolone with a reducing agent thereby cleaving the ring; reacting the resulting sulfhydryl group with a color forming reagent whose color development is directly proportional to the concentration of the isothiazolone and measuring the isothiazolone concentration via a calibrated color comparator or colorimeter.
Inventors
- 👤 Wolfgang G. Geyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:54
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22; Y; Y10; Y10T; Y10T436/00; Y10T436/14; Y10T436/141111; Y10T436/25; Y10T436/25375; Y10T436/255
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
70 words
A quantitative method for the colorimetric determination of microlevels of substituted and unsubstituted isothiazolones which comprises: adsorbing the isothiazolone on a support; reductively cleaving the S-N bond of the isothiazolone ring with a hydride selected from the group consisting of sodium borohydride, lithium borohydride, and alkyl aluminum hydride to form a thiol; adding a color forming reagent to the cleaved compound; and determining the concentration of the isothiazolone by colorimetry.
Claim 2
Dependent Claim
70 words
A quantitative method for the colorimetric determination of microlevels of substituted and unsubstituted isothiazolones which comprises: adsorbing the isothiazolone on a support; reductively cleaving the S-N bond of the isothiazolone ring with a hydride selected from the group consisting of sodium borohydride, lithium borohydride, and alkyl aluminum hydride to form a thiol; adding a color forming reagent to the cleaved compound; and determining the concentration of the isothiazolone by colorimetry.
Claim 3
Dependent Claim
93 words
A method according to claim 1 wherein the isothiazolone is of the formula: ##SPC5## wherein R is a substituent selected from the group consisting of hydrogen, (C 1 -C 10 ) alkyl and (C 3 -C 6 ) cycloalkyl; X and Y are independently hydrogen, chlorine or bromine or, when taken together form a substituted or unsubstituted benzene ring to give a compound of the formula: ##SPC6## wherein Z is methyl, ethyl, halogen, nitro, methoxy, or cyano, and n is zero to two and the acid addition salts and metal salt complexes thereof.
Claim 4
Dependent Claim
14 words
A method according to claim 2 wherein the isothiazolone is in an aqueous medium.
Claim 5
Dependent Claim
14 words
A method according to claim 3 wherein the support is a polymeric macroreticular adsorbent.
Claim 6
Dependent Claim
14 words
A method according to claim 4 wherein the color forming reagent is 5,5'-dithio-bis-(2-nitrobenzoic acid).
Claim 7
Dependent Claim
46 words
A method according to claim 2 wherein the isothiazolone is in a non-aqueous medium which involves the following additional steps: extracting out the isothiazolone with a suitable organic solvent; removing the solvent; and dissolving the isothiazolone in an aqueous medium before adsorbing it on the support.
Claim 8
Dependent Claim
14 words
A method according to claim 6 wherein the support is a polymeric macroreticular adsorbent.
Claim 9
Dependent Claim
14 words
A method according to claim 7 wherein the color forming reagent is 5,5'-dithio-bis-2-(nitrobenzoic acid).
Claim 10
Dependent Claim
14 words
A method according to claim 8 wherein the isothiazolone is 2-methyl-5-chloro-4-isothiazolin-3-one calcium chloride complex.
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) | 1979-08-17 | 1980-02-16 | 1980-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-17 | 1984-02-16 | 1984-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-17 | 1988-02-16 | 1988-08-17 | $7700.00 | Window Closed / Lapsed |