ATOMIC SPECTROSCOPY WITH SURFACE-WAVE PLASMAS

The use of microwave induced plasmas, particularly of surface wave pla smas, as detectors in atomic emission spectrometry for elemental analy sis is reviewed. Surface wave plasmas have been produced at low HF pow er and used as gas chromatographic detectors. The analytical performan ces for the detection of non-metals with a Fourier transform spectrome ter and a two-channel filter unit are reported. The excitation behavio r of nonmetals in helium-based mixed gas-plasmas has also be studied. In particular, the effect of power and of nitrogen concentration on th e bromine emission has been systematically investigated. A nine-fold i mprovement of the detection limits for bromine can be obtained in a hi gh power (900 W) helium-nitrogen (0.1-0.2%) plasma.