Helium source microwave-induced plasma mass spectrometric detection in the analysis of gas-chromatographic eluates

Abstract

An atmospheric- and a low-pressure helium microwave-induced plasma have been coupled to a mass spectrometer for the detection of halogenated compounds. The atmospheric-pressure plasma system involved the use of a capillary gas chromatograph for the speciation of halogenated compounds and gave picogram sensitivities for both bromine and iodine. The atmospheric-pressure plasma was found to have elevated backgrounds at masses 35 and 37. These elevated backgrounds led to a low-pressure torch design which reduced these and other low-mass backgrounds. The analysis of halogenated compounds using the low-pressure torch was limited to the flow injection of methyl chloride and methyl bromide.