US4509964A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fused silica capillary column
Assignee: Schneider Electric Systems USA Inc
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Filing: 1984-01-04
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Granted: 1985-04-09
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Expires: 2004-01-04
Abstract
Abstract A gas chromatographic column comprising synthetic fused silica tubing irradiated in its raw state with gamma radiation of pre-selected dosage and dosage rate. The column further comprises a stationary phase coating of cyano-silicone immobilized and stabilized by cross-linking in situ by means of further irradiation by gamma radiation.
Inventors
- 👤 John A. Hubball
- 👤 Eugene F. Barry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:52
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/60; G01N30/6052; G01N30/6073
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
60 words
The method of making a fused silica capillary column for use in gas chromatography comprising the steps of: irradiating fused silica capillary tubing with gamma radiation while the inner wall thereof is in a raw state, free from any coating; and thereafter applying a polar stationary phase coating to the inner wall of said tubing to form a chromatographic column.
Claim 2
Independent Claim
60 words
The method of making a fused silica capillary column for use in gas chromatography comprising the steps of: irradiating fused silica capillary tubing with gamma radiation while the inner wall thereof is in a raw state, free from any coating; and thereafter applying a polar stationary phase coating to the inner wall of said tubing to form a chromatographic column.
Claim 3
Dependent Claim
13 words
The method of claim 1, wherein said stationary phase is a silicone compound.
Claim 4
Dependent Claim
11 words
The method of claim 2, wherein said stationary phase is cyano-containing.
Claim 5
Dependent Claim
13 words
The method of claim 1, wherein said stationary phase is stabilized by cross-linking.
Claim 6
Dependent Claim
20 words
The method of claim 4, wherein said cross-linking is effected by a further irradiation of said column with gamma radiation.
Claim 7
Dependent Claim
27 words
The method of claim 4, wherein said cross-linking is effected at least in part by irradiating the stationary phase material prior to its application to the column.
Claim 8
Dependent Claim
12 words
A chromatographic column produced in accordance with the process of claim 1.
Claim 9
Dependent Claim
56 words
A chromatographic capillary column of fused silica prepared by a process comprising the steps of: irradiating fused silica capillary tubing with gamma radiation while said fused silica is in a raw state, free of any coating; and thereafter applying a polar stationary phase coating to the inner wall of said tubing to form the chromatographic column.
Claim 10
Dependent Claim
56 words
A chromatographic capillary column of fused silica prepared by a process comprising the steps of: irradiating fused silica capillary tubing with gamma radiation while said fused silica is in a raw state, free of any coating; and thereafter applying a polar stationary phase coating to the inner wall of said tubing to form the chromatographic column.
Claim 11
Dependent Claim
13 words
The column of claim 8, wherein said stationary phase includes a silicone compound.
Claim 12
Dependent Claim
11 words
The column of claim 9, wherein said stationary phase includes cyano.
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) | 1988-04-08 | 1988-10-08 | 1989-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-08 | 1992-10-08 | 1993-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-08 | 1996-10-08 | 1997-04-09 | $7700.00 | Window Closed / Lapsed |