Pulsed coulometric detection with automatic rejection of background signal in surface-oxide catalyzed anodic detections at gold electrodes in flow-through cells
US4939924A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 1988 |
| Grant date | Jul 10, 1990 |
| Priority date | — |
| Expiry date | Sep 26, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/423
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A variation of Pulsed Coulometric Detection (PCD) is described in which the detection potential is scanned in a cyclic fashion during current integration to achieve automatic and virtual elimination of baseline drift caused by surface roughening and changes in pH. The technique is examined at a Au electrode for flow-injection determination if thiourea which is typical of numerous sulfur compounds whose anodic reactions are catalyzed by formation of surface oxide. The baseline decays quickly to a near-zero equilibrium value following start-up and is unchanged for a pH step of ca. 2 units. The technique is concluded to be compatible with pH-gradient chromatography.
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