US3693403A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas analysis apparatus and method using parallel gas density detectors and different carrier gases to determine molecular weight
Assignee: Chemalytics Corp
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Filing: 1970-11-09
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Granted: 1972-09-26
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Expires: 1990-11-09
Abstract
Abstract A method and apparatus are provided for measurement of a function of the molecular weight of a volatile chemical compound of a sample and the absolute weight contained therein by dividing a flow of volatilized sample into a plurality of portions having a fixed volume proportion to each other, trapping the chemical compound from each of said portions separately in trapping means, transferring the chemical compound of each of said portions into different carrier gases, said carrier gases differing in molecular weight from each other and from the chemical compound of the sample to form separate flows and passing the separate flows through separate means of the recording gas density cell type whereby signal outputs are obtained, the ratio of any two signal outputs being a function of the molecular weight of the compound, the means for trapping of the chemical compound to be measured preferably including a chromatographic tube when more than a single component is present.
Inventors
- 👤 Donald G Paul
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:48
CPC Classifications
G; G01; G01N; G01N9/00; G01N30/00; G01N30/02; G01N30/88; G01N30/04; G01N30/06; G01N30/12; G01N2030/121; G01N30/10; G01N30/26; G01N30/38; G01N30/46; G01N30/466; G01N30/62; G01N30/64; G01N30/66; G01N30/78
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
25 words
Apparatus of claim 1 in which the sample dividing means is a means for dividing the sample into a plurality of flows not exceeding four.
Claim 2
Dependent Claim
22 words
Apparatus of claim 2 in which the sample dividing means is a means for dividing the sample into a pair of flows.
Claim 3
Dependent Claim
25 words
Apparatus of claim 3 in which each trapping means is heat controlled and is a high surface area vessel having substantially no differential retention properties.
Claim 4
Dependent Claim
69 words
Apparatus of claim 3 in which each trapping means is a two stage trapping means wherein the first stage includes means for transferring a plurality of chemical compound components from each sample flow as a mixture into a carrier gas and the second stage includes means for separating chromatographically said plurality of chemical compound components into a series of flows of individual chemical compounds in the respective carrier gas.
Claim 5
Dependent Claim
61 words
Apparatus of claim 5 in which the two stage trapping means includes a first stage trapping means having substantially no differential retention properties for entraining the respective separated chemical portions and a second stage trapping means having substantial differential retention properties and valving means therebetween whereby flow from the first stage trapping means to the second stage trapping means is controlled.
Claim 6
Independent Claim
173 words
A method for measurement of the molecular weight of a volatile chemical compound component of a sample comprising: chemical compound into a plurality of flows of portions having a fixed quantitative ratio to each other; a. simultaneously dividing a sample containing a chemical compound into a plurality of flows of portions having a fixed quantitative ratio to each other; b. simultaneously trapping the chemical compound from each of said portions and simultaneously transferring said chemical compound of each of said portions into a different carrier gas to form a plurality of sample flows in respective different carrier gases; c. simultaneously passing each said flow into a separate signal recording gas density detector of the gas density cell type in which each gas density cell is provided with a flow reference gas of the same composition as the carrier gas in the sample flow; and d. simultaneously recording the signal outputs of the detector cells during the period of flow, said signal outputs being a function of the molecular weight of said chemical compound.
Claim 7
Dependent Claim
53 words
The method of claim 7 in which the saMple consists of an individual chemical compound in a carrier gas and steps b and c comprise the steps of trapping each chemical compound, purging the carrier gas therefrom with said different carrier gas and detrapping each chemical compound into its respective different carrier gas.
Claim 8
Dependent Claim
16 words
The method of claim 7 in which the plurality of sample portions does not exceed four.
Claim 9
Dependent Claim
70 words
The method of claim 9 in which the sample is transferred into a first carrier gas of different chemical structure than the chemical compound component of the sample to be measured to form a sample flow and the sample flow is divided into a plurality of sample flows, from which flows each compound component is subsequently separated from the first carrier gas before being transferred into said different carrier gas.
Claim 10
Dependent Claim
93 words
The method of claim 10 in which the sample contains a plurality of chemical components to be measured and the plurality of chemical components is first trapped from the carrier gas as a plurality of mixtures of chemical components, each said mixture is transferred into a different carrier gas and chromatographically separated into a plurality of flows in respectively different carrier gases, each flow comprising a flow of the chemical compound component in the respective carrier gas serially separated from each other in order of the chromatographic retention time of each chemical compound.
Claim 11
Dependent Claim
45 words
The method of claim 11 in which the chemical components of the mixtures in different carrier gases are chromatographically separated on chromotographic columns having different adsorbent properties so as to provide a plurality of flows in which the retention times are different in each flow.
Claim 12
Dependent Claim
24 words
The method of claim 12 in which both retention time and molecular weight are determined from the data as a means of chemical identification.
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) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |