An trace analyzer apparatus and method useful in semiconductor processing for measuring trace impurities in gases and liquids comprising a gas chromatograph serving to replace a bulk gas in a composition of bulk gas including contaminants in a bulk gas stream with a carrier gas having a higher ionization potential than that of said contaminants, where such gas chromatograph is connected to a hollow electrode (14) for initiating ionization of said contaminants by electrical discharge, where such electrode is electrically isolated from a source housing (44) and adjacent to a skimmer plate (16) that ionizes trace contaminants that are measured using a mass spectrometer, is disclosed.