Determination of Impurity Gas in H₂ with Micro Gas Chromatography

In order to meet the requirements of the process system such as ISS, TEP and SDS for the quality of intake air, it is necessary to establish an accurate, fast, and high-precision impurity gas analysis method. Aiming at the gas components He, Ne, N₂, Ar, CH₄, CO and CO₂ with volume fractions of 10^-2~10^-3 in H₂, a miniature channel equipped with one PoraPLOT U channel and one MS5 channel was utilized in this work firstly. Using H₂ as the carrier gas, an analysis method for impurity gases in H₂ was established. Under optimal conditions, the measurement accuracy of impurity gas components is better than 0.2%, the relative measurement error is less than 0.5%, the resolution is greater than 1.5, the detection limit is 1.3×10^-6~8.5×10^-6, and the quantification limit is 4.5×10^-6~36.3×10^-6, and the analysis time is less than 2.5 min. On the basis of the above conditions, the feasibility of measuring impurity gases in H₂ with He, Ne and Ar as the carrier gas respectively was discussed, and the standard spectrum under the best measurement conditions was obtained. The research method can meet the analysis requirements of the process system for the intake air, and can be extended to the analysis of impurity components in other hydrogen isotope gases.