An analytical technique for measuring both total protium (H) and total deuterium (D) in a gas mixture containing protium (H2), deuterium (D2), and hydrogen-deuterium (HD) has been developed. This technique uses a micro-gas chromatograph (uGC) with two molecular sieve columns each with thermal conductivity detectors. The carrier gas for one column is deuterium and the second column uses protium as the carrier gas. Laboratory tests have shown that, when used in this configuration, the micro-gas chromatograph can measure both total protium and total deuterium each with a detection and quantification limit of less than 20 ppm. This is a low-cost technology that can be used to provide rapid results (less than 1 min), that are comparable with analytical results from very expensive, high resolution low mass, magnetic sector mass spectrometers.