气相色谱法测定煤层瓦斯中低浓度氢气和氦气

Determination of Trace Molecular Helium and Hydrogen Gases from Coal Mining Underground by Gas Chromatography

利用HP 5890气相色谱仪热导检测器小热导池高灵敏度及大进样量的特点,建立了煤层中低浓度He、H2的气相色谱测定方法,并可同时测定常量CH4.对气相色谱工作条件进行了优化,确定的最佳工作条件是:13X分子筛填充柱,热导检测器(TCD),载气流速为35～42 mL/min,色谱柱温度 50 ℃,汽化室温度 50 ℃,检测室温度 100 ℃,3 mL定量环.He、H2的线性工作范围分别为0.95～19 μL/L和2.4～48 μL/L,RSD(n=8)分别为1.60%和4.54%,方法的检出限为0.5 μL/L.实验了铝箔气袋、橡胶气球和盐水瓶不同包装的样品进样方式及测定情况,结果表明铝箔气袋是最佳选择,盐水瓶次之,橡胶气球对气体有一定的吸附作用.

This paper describes a method for determination of the H2 and He at low concentration from coal mining underground by gas chromatography. The method is also available for the determination of CH4 from coal. The working conditions of gas chromatography were optimized. A 13X molecule sieve packed column and thermal conductivity detector （TCD） were used with optimized working conditions of carrier gas flow rate at 35 -42 mL/min, column temperature at 50 ℃, injector temperature at 50 ℃ and detector temperature at 100 ℃. The linear ranges for He and H2 are 0.95 - 19μL/L and 2.4 - 48μL/L with precision of 1.60% RSD and 4.54% RSD （ n = 8） , respectively. The detection limits for He and H2 are 0.5μL/L. Three kinds of packing materials including Al-foil bags, rubber balls and salt water-filling glass bottles were tested. The results show that Al-foil bag is the best one, the salt water-filling glass bottle property especially for the gases is next and the rubber ball is not suitable for sampling due to its gas-adsorption of He and H2.