Behaviour and analytical applications of a modulated power microwave-induced plasma (surfatron)

Abstract

An a.c. modulated power has been applied to a microwave-induced plasma (MIP) produced by a surfatron structure. A temporal study of the plasma behaviour was carried out with a boxcar averager. It was confirmed that the best signal intensity was obtained at about 50 Torr and it was shown that inter-element effects are concentration dependent in the MIP source. An application of source modulation to sulphur detection in gas chromatography is given, with detection limits lying in the picogram range.