Patent US3725232A successfully refreshed from Google Patents.
US3725232A
Expired / Lapsed
US
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Detection method and apparatus for chromatography
Assignee: Individual
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Filing: 1971-02-23
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Granted: 1973-04-03
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Expires: 1991-02-23
Abstract
Abstract Small amounts of dissolved impurities in an eluent for chromatography and which might interfere with the monitoring of a chromatogram by very sensitive, in particular electrochemical detectors, are removed by passing the eluent, on its way to a chromatographic system, through an electrochemical cleaning device. The device is divided into two parallel passages by a porous wall impregnated with a salt bridge medium. The one passage through which the eluent flows, is packed with a porous conductive medium serving as one electrode and the other passage contains a reference electrode, e.g. calomel or silver chloride. An appropriate voltage applied across the electrodes causes the electrochemical elimination of the interfering impurities.
Inventors
- 👤 V Pretorious
- 👤 H Hahn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:31
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/84; G01N30/26; G01N30/38; G01N2030/387; G01N30/62; G01N2030/626; G01N30/64; G01N2030/645; G01N30/04; G01N30/06; G01N30/14; G01N30/28; G01N30/34
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
16 words
A process as claimed in claim 1 wherein the detection step is an electrochemical detection step.
Claim 2
Dependent Claim
43 words
A process as claimed in claim 2 wherein a part of the eluent is fed from the passage through a blank separating medium and hence to a compensatory detection step coupled to the aforesaid electrochemical detection step for the reduction of background noise.
Claim 3
Dependent Claim
32 words
A process as claimed in claim 1 wherein the voltage adapted to remove said impurities is set to remove all impurities capable of being detected under the conditions of the detection step.
Claim 4
Dependent Claim
108 words
Apparatus for chromatographic analysis comprising, connected in that sequence, a feed passage for an eluent, an eluent cleaning device, an inlet portion of a chromatographic separating device, said separating device itself and an eluate monitoring device, said eluent cleaning device comprising a flow-through passage for the eluent, said passage comprising an electrode, a wall of the passage being at least partly permeable by virtue of pores through said wall which are filled with a salt bridge medium to form a salt bridge leading to a further electrode provided on the side of the wall opposite the passage and further comprising terminals for applying a voltage across the electrodes.
Claim 5
Dependent Claim
53 words
Apparatus as claimed in claim 5 wherein the eluate monitoring device comprises an electrochemical detector cell adapted for the eluate to flow therethrough, the eluate being said eluent after having passed successively through the feed passage, the flow through passage of the eluent cleaning device, the inlet portion and the chromatographic seParating device.
Claim 6
Dependent Claim
45 words
Apparatus as claimed in claim 6 comprising a blank column having flow properties essentially the same as those of the chromatographic separating device and being connected between the eluent cleaning device and a compensating cell of a construction essentially similar to the electrochemical detector cell.
Claim 7
Dependent Claim
48 words
The apparatus as claimed in claim 5 wherein the electrode in the passage is formed by a porous electrically conductive medium filling said passage and wherein said further electrode is selected from the group consisting of calomel and silver chloride electrodes and fills a space adjoining said passage.
Claim 8
Dependent Claim
41 words
An apparatus as claimed in claim 8 wherein said passage is surrounded by a porous tube inside the walls of a larger chamber, said further electrode being contained in the space between the porous tube and the walls of the chamber.
Claim 9
Dependent Claim
42 words
Apparatus as claimed in claim 5 comprising a tubular body subdivided by a porous partition, constituting said at least partly permeable wall, into said passage containing said firstmentioned electrode and a further passage parallel to the firstmentioned passage containing said further electrode.
References Cited (Backward Citations)
US673452A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |