Patent US4837414A successfully refreshed from Google Patents.
US4451374A
Expired / Lapsed
US
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Liquid chromatographic method and post-column effluent treatment for detection and separation at optimized pH
Assignee: Dow Chemical Co
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Filing: 1983-02-14
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Granted: 1984-05-29
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Expires: 2003-02-14
Abstract
Abstract Reagent is added to liquid chromatographic effluent to increase detection sensitivity of sample bands, or to enhance sensitivity with respect to interfering bands which overlap sample bands of interest, using one or more hollow fibers immersed within mobile reagent which is permeated through the walls of the fibers and, thus, ultimately diffused into the column effluent.
Inventors
- 👤 Dennis P. Peterson
- 👤 James C. Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:37
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/84; B; B01; B01D; B01D15/00; B01D15/08; B01D15/10; B01D15/24; B01D15/245; B01J; B01J19/00; B01J19/24; B01J19/2475; B01J4/00; B01J4/001; B01J4/04; B01J2219/00; B01J2219/00049; B01J2219/00051; B01J2219/00159; G01N1/00; G01N1/28; G01N1/38; G01N2001/381; G01N2030/8423; G01N2030/8429; G01N2030/8435
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
131 words
Liquid chromatographic apparatus comprising a silica based chromatographic column means, means to add sample to the chromatographic column means, a reservoir of eluent of a pH nondetrimental to the silica chromatographic column means, a chromatographic pump means to add the eluent to the chromatographic column means, whereby the sample is eluted through the chromatographic column means, and component species thereof appear in chromatographically displaced form in the effluent of the chromatographic column means, the improvement which comprises a post-column reactor comprising a hollow fiber membrane through which the effluent of the chromatographic column means is fed to a liquid chromatographic detector, a pH modifying mobile reagent, said hollow fiber being in permeation contact with the mobile reagent for permeation transfer of the reagent into the effluent of the chromatographic column means.
Claim 2
Dependent Claim
131 words
Liquid chromatographic apparatus comprising a silica based chromatographic column means, means to add sample to the chromatographic column means, a reservoir of eluent of a pH nondetrimental to the silica chromatographic column means, a chromatographic pump means to add the eluent to the chromatographic column means, whereby the sample is eluted through the chromatographic column means, and component species thereof appear in chromatographically displaced form in the effluent of the chromatographic column means, the improvement which comprises a post-column reactor comprising a hollow fiber membrane through which the effluent of the chromatographic column means is fed to a liquid chromatographic detector, a pH modifying mobile reagent, said hollow fiber being in permeation contact with the mobile reagent for permeation transfer of the reagent into the effluent of the chromatographic column means.
Claim 3
Dependent Claim
14 words
The apparatus of claim 1 wherein said post-column reactor comprises multiple hollow fiber membranes.
Claim 4
Dependent Claim
27 words
The apparatus of claim 1 comprising a reservoir means containing acid or base mobile reagent, wherein the reservoir means is of a type noncontinuously replenished by reagent.
Claim 5
Dependent Claim
11 words
The apparatus of claim 1 comprising a photometer as the detector.
Claim 6
Dependent Claim
136 words
Method of analyzing samples by liquid chromatography comprising adding sample to a silica based chromatographic column means, adding eluent to the chromatographic column means effective to chromatographically displace species of the sample from the chromatographic column means, whereby chromatographically displaced sample species appear ultimately in the effluent of the chromatographic column means, the eluent being at a pH in the range nondetrimental to the silica chromatographic column means, the improvement which comprises feeding the effluent of the chromatographic column means through the internal bore of a hollow fiber membrane, ultimately to a liquid chromatographic detector, and prior to detection, using the hollow fiber membrane for permeation transfer of a mobile reagent into the effluent of the chromatographic column means to enhance the sensitivity of detection of the method by effecting a pH change in the effluent.
Claim 7
Dependent Claim
136 words
Method of analyzing samples by liquid chromatography comprising adding sample to a silica based chromatographic column means, adding eluent to the chromatographic column means effective to chromatographically displace species of the sample from the chromatographic column means, whereby chromatographically displaced sample species appear ultimately in the effluent of the chromatographic column means, the eluent being at a pH in the range nondetrimental to the silica chromatographic column means, the improvement which comprises feeding the effluent of the chromatographic column means through the internal bore of a hollow fiber membrane, ultimately to a liquid chromatographic detector, and prior to detection, using the hollow fiber membrane for permeation transfer of a mobile reagent into the effluent of the chromatographic column means to enhance the sensitivity of detection of the method by effecting a pH change in the effluent.
Claim 8
Dependent Claim
23 words
The method of claim 5 using multiple hollow fiber membranes connected between the chromatographic column means and detector and immersed within mobile reagent.
Claim 9
Dependent Claim
16 words
The method of claim 5 wherein said mobile reagent is contained within a noncontinuously replenished reservoir.
Claim 10
Dependent Claim
10 words
The method of claim 5 wherein the sample comprises nitrophenols.
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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) | 1987-05-29 | 1987-11-28 | 1988-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-29 | 1991-11-28 | 1992-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-29 | 1995-11-28 | 1996-05-29 | $7700.00 | Window Closed / Lapsed |