濃縮分離-ガスクロマトグラフ法による高純度ヘリウム中の微量不純物の定量

概要

論文の詳細を見る
A technique has been established for detemining volume parts per million (vpm) levels of gas impurities (H_2, Ar, O_2, N_2, CH_4, CO, and CO_2) in helium using a preconcentration-gas chromatographic method. An advantage of the proposed technique is that concentration and development of impurities can be mainly effected in a trap. The impurities were concentrated by flowing a known volume of helium sample through a cold adsoption trap containing 1ml of Molecular Sieve 5A at liquid nitrogen temperature (-190℃). The temperature of the trap was raised from -190℃ to 300℃ under helium carrier stream, and the impurities were transferred from the trap into analytical column (activated charcoal, 3mmφx1000mm) for separation and deteminadon. The impurities {(3〜150)μl STP} were completely recovered by this method. The detection limits for impurities except hydrogen were less than 0.5 vpm in helium.
社団法人日本分析化学会の論文
1975-02-10