Simultaneous determination of nitrogen and oxygen in uranium nitride by an inert gas fusion method

The simultaneous determination of nitrogen and oxygen in uranium nitride using a thermal conductivity detector and a non-dispersive infrared spectrometer after fusion in an inert gas atmosphere has been proposed. The loss of nitrogen by oxidation of the sample before analysis is prevented by pulverizing, weighing and packing the sample into a nickel capsule in a glove-box with a high-purity argon atmosphere. After the encapsulated sample is transferred into a graphite crucible, it is heated to approximately 2800°C by a resistance heating furnace under a helium carrier gas. The gas extracted from the fused sample is split into about 1/5 and 4/5 by adjusting a pressure regulator and a needle valve. Extracted nitrogen as N₂ and oxygen as CO are simultaneously determined by thermal conductivity detector for N₂ and non-dispersive infrared spectrometer for CO, respectively. Only 30 mg of the sample is used, and analysis requires about 10 min. No specific skills for glove-box work are necessary. For the determination of uranium nitride, the relative standard deviations have been about 1.2% for nitrogen and 2.7% for oxygen, respectively.