A new method for the determination of O/sub 2/ in metals is described. The sample is dropped into molten Pt in a graphite crucible. The oxide in the sample reacts with C to form CO, which is swept out by a stream of argon at atmospheric pressure. The CO is oxidized to CO/sub 2/, which is condensed in a capillary trap and measured with a capillary manometer. The apparatus is sensitive to 0.3 mu g of O/sub 2/, and routine 50-mg Pu samples give a standard deviation of 7 ppm or 0.35 mu g. Pu samples with added O/sub 2/ gave a standard deviation of 1.5 mu g or 2% of the total oxygen, with no significant bias. The apparatus is simple and rugged permitting replacement of parts without glassblowing. The speed is superior to vacuum fusion methods, most samples requiring only twelve minutes for analysis.