Element specific radio frequency discharge helium plasma detector for chromatography
US4851683A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 9, 1987 |
| Grant date | Jul 25, 1989 |
| Priority date | — |
| Expiry date | Mar 9, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N30/74
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for element specific detection in chromatogragphic eluents. The apparatus is comprised of a radio frequency discharge between electrodes in helium, and utilizes a low-resolution plasma emission spectrometer to monitor selected spectral emissions produced when the helium discharge decomposes and excites the atomic constituents in chromatographic column effluents. The spectrometer is tuned to an atomic emission line in the near-infrared portion of the spectrum, and the emission intensity from the discharge region of a selected line is used to monitor the concentration of the element producing that line. Acceptable detector sensitivity is achieved by the use of a high-throughput optical system. Selectivity is achieved by a combination of correct line selection, plasma and carrier gas purification, and plasma gas doping.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.