EP0577263A1
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EP
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An impregnated support, apparatus and method for determining the concentration of readily oxidizable organic vapors in gas samples
Assignee: SAC Corp
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Filing: 1993-05-28
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Granted: —
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Expires: 2013-05-28
Abstract
Abstract The present invention provides a reagent, an apparatus and a method for semi-quantitatively estimating the concentration of readily oxidizable organic vapors in a gas sample, as for example ethanol in a human breath sample. The ethanol-sensitive solid indicator is a solid support which contains a permanganate salt and is wetted by a strongly acidic or alkaline solution. In the presence of ethanol the indicator produces a clearly visible color change. The apparatus contains the indicator and provides a pathway for a gas sample through the indicator. The method allows estimation of the organic-vapor content of a gas sample by comparing the volume of indicator which changes color in response to the gas sample with the volume which changes color in response to a known-concentration standard.
Inventors
- 👤 Francis Pei-Kang Liu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 16:53
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/02; G01N29/036; G01N33/00; G01N33/48; G01N33/50; G01N33/98; G01N31/00; G01N31/22; G01N31/223; Y; Y10; Y10S; Y10S436/00; Y10S436/90; Y10T; Y10T436/00; Y10T436/20; Y10T436/203332; Y10T436/204165
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
28 words
An impregnated support, suitable for the colorimetric estimation of readily oxidizable organic vapors in gases, which comprises a free-flowing, solid particulate support having adsorbed thereon a permanganate salt.
Claim 2
Dependent Claim
20 words
An impregnated support as claimed in claim 1, wherein the support is selected from molecular sieves, silica, alumina, and magnesia.
Claim 3
Dependent Claim
42 words
An impregnated support as claimed in claim 1 or claim 2, wherein the permanganate salt is potassium permanganate and is present on the support in an amount of from about 0.7 to about 14 milligrams of potassium permanganate per gram of support.
Claim 4
Dependent Claim
39 words
An activated, impregnated support, suitable for the colorimetric estimation of readily oxidizable organic vapors in gases, which comprises an impregnated support as claimed in any preceding claim, wherein the support has been wetted with an acidic or alkaline solution.
Claim 5
Dependent Claim
35 words
An activated, impregnated support as claimed in claim 4, wherein the volume of the acidic or alkaline solution is in a ratio to the weight, in grams, of the support of from 0.1:1 to 1:1.
Claim 6
Dependent Claim
33 words
An activated support as claimed in claim 4 or claim 5, wherein the solution is an alkaline solution and is an aqueous solution of from 10% to 50%, by weight, of sodium hydroxide.
Claim 7
Independent Claim
47 words
An apparatus for colorimetric estimation of the concentration of readily oxidizable organic vapors in gases, which comprises a transparent or translucent vessel having an inlet opening and an outlet opening, and disposed within the vessel an impregnated support as claimed in any of claims 1 to 3.
Claim 8
Dependent Claim
27 words
An apparatus as claimed in claim 7, wherein the vessel is cylindrical, and the inlet and outlet openings are disposed at either end of the cylindrical vessel.
Claim 9
Dependent Claim
33 words
An apparatus as claimed in claim 7 or claim 8, wherein the outlet opening of the vessel is connected to a means for determining the volume of gas which passes through the vessel.
Claim 10
Independent Claim
81 words
An apparatus as claimed in any of claims 7 to 9, wherein an acidic or alkaline solution is disposed within the vessel nearer the inlet opening than the support, and is separated from the support by a barrier disposed within the vessel, the barrier being sufficiently porous to allow the solution to be forced under pressure through the barrier to contact the support, but not sufficiently porous to allow the solution to flow through the barrier by capillary action or gravity.
Claim 11
Dependent Claim
22 words
An apparatus as claimed in claim 10, wherein the barrier is glass fibers, fritted ceramic, a stainless-steel screen, or a copper screen.
Claim 12
Independent Claim
70 words
An apparatus as claimed in any of claims 7 to 9, wherein the vessel comprises a flexible, non-frangible tube, an acidic or alkaline solution is disposed within the vessel nearer the inlet opening than the support, and the solution is separated from the support by an impervious, frangible barrier disposed within the tube in such a manner as to be broken to release the solution when the vessel is flexed.
Claim 13
Dependent Claim
20 words
An apparatus as claimed in claim 12, wherein the frangible barrier is a glass barrier which entirely surrounds the solution.
Claim 14
Dependent Claim
91 words
A process for estimating the concentration of readily oxidizable organic vapors in a gas sample of known volume, which comprises contacting the gas sample with an activated, impregnated support as claimed in any of claims 4 to 6, observing the volume of support in which a color change occurs, and estimating the amount of readily oxidizable organic vapors in the sample by comparison to the volume of activated, permanganate-impregnated support which changes color in response to a gas sample of similar volume containing a known concentration of readily oxidizable organic vapors.
Claim 15
Dependent Claim
38 words
A process as claimed in claim 14, wherein the gas sample is a sample of human breath, the readily oxidizable organic vapor is ethanol, and the breath sample is blown through the support by a human test subject.
Claim 16
Dependent Claim
43 words
A process as claimed in claim 15, wherein the alkaline or acidic solution and the support are initially disposed at separate locations within an tube, and the solution is caused to wet the support by the breath sample being blown through the tube.
Claim 17
Dependent Claim
34 words
A process as claimed in claim 16, wherein the alkaline or acidic solution is contained in a frangible ampoule, and the ampoule is broken immediately before the breath sample is blown through the tube.
Claim 18
Dependent Claim
72 words
A process as claimed in any of claims 14 to 17, wherein the support, for example molecular sieves, contains from 3 to 7 milligrams of potassium permanganate per gram of support, the gas sample is a sample of human breath, the readily oxidizable organic vapor is ethanol, the breath sample is blown through the support by a human test subject, and the volume of the sample is from 200 to 250 milliliters.
Claim 19
Dependent Claim
50 words
Use, in the colorimetric estimation of readily oxidizable organic vapors in gases, of an impregnated support as claimed in any of claims 1 to 3, an activated, impregnated support as claimed in any of claims 4 to 6, or an apparatus as claimed in any of claims 7 to 14.
References Cited (Backward Citations)
US2591691A
Cited
US3725007A
Cited
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