提出了合金吸气剂除杂-气相色谱法测定混合气体中氪、氙含量的方法。样品通过减压进样装置进入气相色谱仪,选用管径为3.18 mm、长度为100 cm的不锈钢管为除杂柱,填装合金吸气剂,以消除氮气、氢气等杂质气体对氪、氙测定的干扰。结果显示:氪、氙的体积分数分别在4.55×10^-4%~2.65×10^-3%,5.60×10^-5%~3.29×10^-4%内与其对应的峰面积呈线性关系,检出限(3S/N)分别1.71×10^-6%,1.65×10^-6%;对混合标准气体重复测定6次,峰面积的相对标准偏差均不大于1.0%;按照试验方法与文献报道的气相色谱-质谱法对6个混合气体样品进行测定,相对偏差的绝对值均不大于1.0%。

A method for the determination of Kr and Xe in gas mixture by gas chromatography with alloy getter for impurities removal was proposed. The sample was entered into the gas chromatograph through the decompression sampling device. The stainless steel tube with diameter of 3.18 mm and length of 100 cm was selected as the impurity removal column, and the alloy getter was filled to eliminate the interferences of nitrogen, hydrogen and other impurities on the determination of Kr and Xe. It was shown that linear relationships between volume fractions of Kr and Xe and their peak areas were kept in the range of 4.55×10^-4%-2.65×10^-3% and 5.60×10^-5%-3.29×10^-4%, respectively, with dection limts (3S/N) of 1.71×10^-6%, 1.65×10^-6%. The standard gas mixture was determined six times, and RSDs of the peak areas were less than 1.0%. The six gas mixture samples were determined according to this method and gas chromatography-mass spectrometry from literature, giving absolute values of relative deviations no more than 1.0%.