An atmospheric pressure microwave-excited emissive argon plasma is evaluated for use as a detector in conventional gas-chromatographic analysis. A range of carbon-, oxygen-, nitrogen- and halogen-containing compounds was investigated in order to optimize the sensitivity, linear working range and plasma operating conditions. For the non-selective determination of carbon-containing compounds, the atomic carbon emission at 247.9 nm was found to be most useful. At this wavelength the sensitivities for all the compounds investigated were directly proportional to the amount of carbon in the compounds. The limit of detection for these compounds at 247.9 nm was 1.94·10 -l0 g of carbon per sec. The atomic lines at 206.2 nm (I) and 470.5 nm (Br) were the best for the selective determination of iodine- and bromine-containing compounds respectively, and a new band emission at 256 nm, characteristic of chlorinecontaining compounds, gave good sensitivity.