Self cleaning electrochemical detector and cell for flowing stream analysis
US4496454A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 19, 1983 |
| Grant date | Jan 29, 1985 |
| Priority date | — |
| Expiry date | Oct 19, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved electrochemical cell and detector which is especially suited for analysis of rapidly changing flowing streams such as found in high performance liquid chromatography is disclosed. A uniquely designed jet made of microbore drawn capillary tubing permits the construction of a cell for very low flow rates that still retains true wall-jet hydrodynamics. The invention prevents changes in cell response in time by periodically cleaning a working electrode in a novel way. Cleaning and detection are both accomplished on a time scale much shorter than the fastest liquid chromatograph peaks by means of a unique three electrode cell design utilizing a small diameter, low capacitance, metal working electrode situated close to a reference electrode. Cleaning is accomplished by means of a non-square wave periodic waveform which is effective in cleaning a wide variety of contaminants through the oxidation and reduction of the working electrode and/or solvent prior to application of one or more working potentials while providing a stable, reproducible detector. The detector thus provides improvements in both sensitivity and bandwidth over the prior art.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.