Gas Chromatography/Mass Spectrometry - Technique for separating chemicals that are volatile and then obtaining a mass spectrum of that chemical. Mass spectrum can then be compared to reference materials for identification.
Gas-Chromatography Mass-Spectroscopy assay
Gas Chromatograph Mass Spec - The instrument separates compounds using a gas chromatograph, and then each compound is run through the Mass Spec to get its molecular weight.
Gas Chromatogaphy/Mass Spectrometry, also used for doping tests that are not CIR, in particular, "quantitative" T/E tests.