Patent US3967928A successfully refreshed from Google Patents.
US3967928A
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Method for quantitatively analyzing substances containing elements other than carbon, hydrogen and oxygen and volatile organic compounds
Assignee: Dow Chemical Co
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Filing: 1974-03-22
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Granted: 1976-07-06
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Expires: 1994-03-22
Abstract
Abstract Method for quantitatively analyzing substances containing elements other than carbon, hydrogen and oxygen by (1) adsorbing such substances on a particulate, substantially dust and contaminant free carbonized product prepared by (A) first partially dehydrochlorinating a normally crystalline vinylidene chloride polymer at temperatures below the melting point of such polymer to an extent of at least about 5 percent of theoretical HCl loss, then (B) completing the dehydrochlorination of such material, in the substantial absence of oxygen, by heating the material to carbonizing temperatures of from about 600°C to about 1200°C; then (2) analyzing the substance adsorbed on such carbonized product.
Inventors
- 👤 Donald D. Schmidt
- 👤 Gary L. Jewett
- 👤 Richard G. Melcher
- 👤 Ritchie A. Wessling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:57
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/12; G01N30/00; Y; Y10; Y10T; Y10T436/00; Y10T436/19; Y10T436/196666; Y10T436/25; Y10T436/25375; Y10T436/255
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
137 words
A method of quantitatively analyzing substances having a vapor pressure of at least 1 Torr at room temperature, said substances containing elements other than carbon, hydrogen and oxygen said method comprising the sequential steps of (1) adsorbing directly from the atmosphere and untreated sample of said substances on a particulate, substantially dust and contaminant free carbonized product prepared by (A) first partially dehydrochlorinating a normally crystalline vinylidene chloride polymer at temperatures less than the melting point of said polymer to an extent of at least about 5 percent of theoretical HCl loss, then (B) completing the dehydrochlorination of the partially dehydrochlorinated polymer, in the substantial absence of oxygen, by heating said polymer to carbonizing temperatures from about 600°C to about 1200°C, then (2) quantitatively analyzing for said substances while said substances remain adsorbed on said carbonized material.
Claim 2
Independent Claim
137 words
A method of quantitatively analyzing substances having a vapor pressure of at least 1 Torr at room temperature, said substances containing elements other than carbon, hydrogen and oxygen said method comprising the sequential steps of (1) adsorbing directly from the atmosphere and untreated sample of said substances on a particulate, substantially dust and contaminant free carbonized product prepared by (A) first partially dehydrochlorinating a normally crystalline vinylidene chloride polymer at temperatures less than the melting point of said polymer to an extent of at least about 5 percent of theoretical HCl loss, then (B) completing the dehydrochlorination of the partially dehydrochlorinated polymer, in the substantial absence of oxygen, by heating said polymer to carbonizing temperatures from about 600°C to about 1200°C, then (2) quantitatively analyzing for said substances while said substances remain adsorbed on said carbonized material.
Claim 3
Dependent Claim
27 words
The method of claim 1 wherein said particulate, substantially dust and contaminant free carbonized product has a surface area of at least about 800 m 2 /g.
Claim 4
Dependent Claim
15 words
The method of claim 2 wherein said normally crystalline vinylidene chloride polymer is polyvinylidene chloride.
Claim 5
Dependent Claim
14 words
The method of claim 3 wherein the substance being analyzed is hydrolytically unstable tetraethylorthosilicate.
Claim 6
Dependent Claim
14 words
The method of claim 3 wherein the substance being analyzed is vinyl chloride monomer.
Claim 7
Dependent Claim
14 words
The method of claim 3 wherein the substance being analyzed is vinylidene chloride monomer.
Claim 8
Dependent Claim
15 words
The method of claim 3 wherein the substance being analyzed is a brominated organic compound.
Claim 9
Dependent Claim
22 words
The method of claim 7 wherein said brominated organic compound is selected from the group consisting of bromochloromethane, ethylene dibromide and bromoform.
Claim 10
Dependent Claim
16 words
The method of claim 3 wherein the substance being analyzed is a mixture of volatile solvents.
Claim 11
Dependent Claim
21 words
The method of claim 3 wherein said substances are quantitatively analyzed by subjecting said substance to a source of neutron activation.
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) | 1979-07-06 | 1980-01-05 | 1980-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-06 | 1984-01-05 | 1984-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-06 | 1988-01-05 | 1988-07-06 | $7700.00 | Window Closed / Lapsed |