US4159894A
Expired / Lapsed
US
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Method for determining formulation and chemical structure of materials by improved pyrolysis gas chromatography
Assignee: Boeing Co
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Filing: 1978-02-13
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Granted: 1979-07-03
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Expires: 1998-02-13
Abstract
Abstract A material containing both volatile and nonvolatile components, such as a compounded high polymer, is analyzed using pyrolysis gas chromatography by directly inserting a sample into a sample injection chamber in contact with a flowing carrier gas stream upstream of a chromatographic column. Prior to inserting the sample, the carrier gas and the sample injection chamber are preheated to a temperature at which the volatile components in the sample will be rapidly vaporized. The temperature to which the injection chamber is preheated is, however, below that which will cause thermal degradation or pyrolysis of the polymeric component of the sample. After substantially all of the vaporizable component is removed from the sample and eluted from the chromatographic column, the polymeric component is pyrolyzed by heating it to a temperature sufficiently high to pyrolyze all of the pyrolyzable components of the sample. The pyrolysates are then carried to the chromatographic column by the carrier gas and eluted from the column. Both the volatile components and the pyrolysates are measured as they are eluted from the column and are graphically recorded to develop a chromatogram and a pyrogram, respectively. The chromatogram represents the specific formulation of the volatile components. The pyrogram represents the chemical structure of the nonvolatile (polymeric) components. Any residue remaining in the injection chamber after pyrolysis can be isolated for subsequent conventional analysis, if desired. Volatile, viscous liquids, such as oils, can also be analyzed by the first step of the procedure outlined above.
Inventors
- 👤 John C. Hu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:21
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/04; G01N30/06; G01N30/12; G01N2030/125
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
160 words
A method for separating and analyzing a sample containing at least one volatile component and at least one nonvolatile, pyrolyzable component comprising: establishing a flow of gaseous carrier fluid a sample injection chamber and thereafter through a chromatographic column, preheating the carrier gas flowing said injection chamber to a first predetermined temperature sufficiently high to vaporize said volatile component and below the pyrolysis temperature of said nonvolatile, pyrolyzable component, inserting said sample into said injection chamber while maintaining the temperature of said carrier gas passing through said chamber at said first predetermined temperature, allowing said volatile component to vaporize and pass through said chromatographic column with said carrier gas, after said volatile component has been vaporized from said sample and eluted from said column, heating said sample to a second predetermined temperature at which said nonvolatile component will be pyrolyzed to a gaseous reaction product, and allowing said reaction product to pass through said chromatographic column with said carrier gas.
Claim 2
Independent Claim
160 words
A method for separating and analyzing a sample containing at least one volatile component and at least one nonvolatile, pyrolyzable component comprising: establishing a flow of gaseous carrier fluid a sample injection chamber and thereafter through a chromatographic column, preheating the carrier gas flowing said injection chamber to a first predetermined temperature sufficiently high to vaporize said volatile component and below the pyrolysis temperature of said nonvolatile, pyrolyzable component, inserting said sample into said injection chamber while maintaining the temperature of said carrier gas passing through said chamber at said first predetermined temperature, allowing said volatile component to vaporize and pass through said chromatographic column with said carrier gas, after said volatile component has been vaporized from said sample and eluted from said column, heating said sample to a second predetermined temperature at which said nonvolatile component will be pyrolyzed to a gaseous reaction product, and allowing said reaction product to pass through said chromatographic column with said carrier gas.
Claim 3
Dependent Claim
30 words
The method of claim 1 further comprising: measuring the amount of said volatile component eluted from said column, and measuring the amount of said reaction product eluted from said column.
Claim 4
Dependent Claim
31 words
The method of claim 2 further comprising: graphically recording the amounts of said volatile component and said reaction product eluted from said column to form a graph characteristic of said sample.
Claim 5
Dependent Claim
30 words
The method of claim 1 wherein said sample is a polymer containing volatile matter and wherein said first predetermined temperature is in the range of 100° C. to 400° C.
Claim 6
Dependent Claim
20 words
The method of claim 4 wherein said first predetermined temperature is in the range of 250° C. to 300° C.
Claim 7
Dependent Claim
20 words
The method of claim 4 wherein said second predetermined temperature is in the range of 600° C. to 1500° C.
Claim 8
Dependent Claim
168 words
In a method for separating and analyzing a sample containing at least one volatile component and a pyrolyzable nonvolatile component wherein the sample is inserted into a carrier gas stream upstream of a chromatographic column, the improvement comprising: first vaporizing said volatile component of said sample in said carrier gas stream by preheating said carrier gas to a first predetermined temperature before contacting said sample with said carrier gas, said first predetermined temperature being sufficiently high to vaporize said volatile component and being below the pyrolysis temperature of said nonvolatile pyrolyzable component, and maintaining said carrier gas at said first predetermined temperature until substantially all of said volatile component of said sample is vaporized and is carried to said chromatographic column by said carrier gas, and thereafter pyrolyzing said nonvolatile component by heating said sample to a second predetermined temperature at which said nonvolatile component will react to form a gaseous pyrolysis product, and allowing said carrier gas to carry said gaseous pyrolysis product to said chromatographic column.
Claim 9
Dependent Claim
168 words
In a method for separating and analyzing a sample containing at least one volatile component and a pyrolyzable nonvolatile component wherein the sample is inserted into a carrier gas stream upstream of a chromatographic column, the improvement comprising: first vaporizing said volatile component of said sample in said carrier gas stream by preheating said carrier gas to a first predetermined temperature before contacting said sample with said carrier gas, said first predetermined temperature being sufficiently high to vaporize said volatile component and being below the pyrolysis temperature of said nonvolatile pyrolyzable component, and maintaining said carrier gas at said first predetermined temperature until substantially all of said volatile component of said sample is vaporized and is carried to said chromatographic column by said carrier gas, and thereafter pyrolyzing said nonvolatile component by heating said sample to a second predetermined temperature at which said nonvolatile component will react to form a gaseous pyrolysis product, and allowing said carrier gas to carry said gaseous pyrolysis product to said chromatographic column.
Claim 10
Dependent Claim
25 words
The method of claim 7 wherein said nonvolatile component is pyrolyzed after substantially all of said volatile component has been eluted from said chromatographic column.
Claim 11
Dependent Claim
40 words
The method of claim 7 further comprising: measuring the amount of said volatile component as it is eluted from said chromatographic column, and measuring the amount of said gaseous is pyrolysis product as it is eluted from said chromatographic column.
Claim 12
Dependent Claim
27 words
The method of claim 7 wherein said sample is a polymer and wherein said first predetermined temperature is in the range of 100° C. to 400° C.
Claim 13
Dependent Claim
20 words
The method of claim 10 wherein said first predetermined temperature is in the range of 250° C. to 300° C.
Claim 14
Dependent Claim
19 words
The method of claim 10 wherein said second predetermined temperature is at least about 600° C. to 1500° C.
Claim 15
Independent Claim
153 words
A method for introducing a viscous liquid into a gas chromatographic column, said column having a sample chamber and an injection port, comprising the steps of: placing a sample of said liquid in a capillary tube, said sample being sufficiently large to fill a portion of said capillary tube, retentively positioning said capillary tube on a sample holder, establishing a flow of carrier gas through said sample chamber and through said gas chromatographic column, preheating said sample chamber and said carrier gas to a predetermined temperature, said predetermined temperature being sufficiently high to vaporize said viscous liquid and being lower than the temperature at which said viscous liquid pyrolyzes, inserting said sample holder including said capillary tube and said viscous liquid sample through said injection port into said sample chamber, such that said carrier gas flows freely aroung said capillary tube, and sealing the region between said injection port and said sample holder.
Claim 16
Independent Claim
153 words
A method for introducing a viscous liquid into a gas chromatographic column, said column having a sample chamber and an injection port, comprising the steps of: placing a sample of said liquid in a capillary tube, said sample being sufficiently large to fill a portion of said capillary tube, retentively positioning said capillary tube on a sample holder, establishing a flow of carrier gas through said sample chamber and through said gas chromatographic column, preheating said sample chamber and said carrier gas to a predetermined temperature, said predetermined temperature being sufficiently high to vaporize said viscous liquid and being lower than the temperature at which said viscous liquid pyrolyzes, inserting said sample holder including said capillary tube and said viscous liquid sample through said injection port into said sample chamber, such that said carrier gas flows freely aroung said capillary tube, and sealing the region between said injection port and said sample holder.
Claim 17
Dependent Claim
25 words
The method of claim 13 wherein said liquid is an oil and said predetermined temperature is in the range of 50° C. to 400° C.
Claim 18
Dependent Claim
19 words
The method of claim 14 wherein said predetermined temperature is in the range of 100° C. to 300° C.
Claim 19
Independent Claim
164 words
a method for separating the components of a viscous liquid comprising: establishing a flow of a carrier gas through a sample injection chamber and thereafter through a gas chromatographic column, preheating said carrier gas flowing through said sample injection chamber and through said chromatographic column to a predetermined temperature, said predetermined temperature being sufficiently high to vaporize said viscous liquid and being lower than the temperature at which said viscous liquid pyrolyzes, placing a sample of said liquid in a capillary tube, said sample being sufficiently large to fill a portion of said capillary tube, retentively positioning said capillary tube on the end of a sample holder, inserting said sample holder into said sample injection chamber and thereby positioning said capillary tube in said chamber such that said carrier gas flows at said predetermined temperature through said chamber and around said capillary tube, thereby vaporizing said liquid sample and carrying the vaporized components of said sample through said chromatographic column in a gaseous state.
Claim 20
Independent Claim
164 words
a method for separating the components of a viscous liquid comprising: establishing a flow of a carrier gas through a sample injection chamber and thereafter through a gas chromatographic column, preheating said carrier gas flowing through said sample injection chamber and through said chromatographic column to a predetermined temperature, said predetermined temperature being sufficiently high to vaporize said viscous liquid and being lower than the temperature at which said viscous liquid pyrolyzes, placing a sample of said liquid in a capillary tube, said sample being sufficiently large to fill a portion of said capillary tube, retentively positioning said capillary tube on the end of a sample holder, inserting said sample holder into said sample injection chamber and thereby positioning said capillary tube in said chamber such that said carrier gas flows at said predetermined temperature through said chamber and around said capillary tube, thereby vaporizing said liquid sample and carrying the vaporized components of said sample through said chromatographic column in a gaseous state.
Claim 21
Dependent Claim
27 words
The method of claim 16 wherein said predetermined temperature is in the range of from 50° C. to 400° C. and wherein said liquid comprises an oil.
Claim 22
Dependent Claim
19 words
The method of claim 17 wherein said predetermined temperature is in the range of 100° C. to 300° C.
Claim 23
Dependent Claim
30 words
The method of claim 16 further comprising: measuring the amount of each vaporized component of said liquid sample as it is eluted in a gaseous state from said chromatographic column.
Claim 24
Dependent Claim
26 words
The methods of claims 13, 16 or 19 wherein said sample of said liquid placed in said capillary tube comprises a predetermined amount of said liquid.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-07-02 | 1983-01-01 | 1983-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-07-02 | 1987-01-01 | 1987-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-07-02 | 1991-01-01 | 1991-07-03 | $7700.00 | Window Closed / Lapsed |