Gas chromatography for measurement of hydrogen isotopes at tritium processing

Abstract Analysis characteristics of the hydrogen isotopes H 2 , HD, HT, D 2 , DT and T 2 were experimentally studied using gas chromatography. A liquid nitrogen cooling column was employed for isotope separation, along with a thermal conductivity detector and a small-volume ionization chamber. The intensity ratio of the six hydrogen isotopes as measured by the thermal conductivity detection was H 2 :HD:HT:D 2 :DT:T 2 = 100:73:61:57:49:43. When the sampling volume was 1 cm 3 , the estimated detection limits for H 2 and T 2 were, respectively, 20 and 50 Pa partial pressure and 200 and 500 ppm concentration. The 0.16-cm 3 ionization chamber could measure only the tritiated molecules, and the estimated detection limit for T 2 gas was 1 ppm. The retention time was reduced when the concentration was greater than 1%. In particular, when it was increased above 10%, identification of neighboring peaks tended to be difficult.