Tests were made for a quantitative decomposition of N2O to N2and for the setting of a statistical equilibrium in mixtures with gaseous nitrogen of nonrandom distribution by emission spectrometric continuous-flow-measurements. Under high-frequency-discharge conditions a residence time of 0.5 seconds is enough for a quantitative decomposition. In this time the statistical balance in the mixture of N2O and N2is reached. The determination of the relative15N abundance in pure N2O or N2gases or in mixtures of N2O and N2in a continuous-flow-emissionspectrometer can directly be achieved.