天然气中烃类单体化合物氢同位素分析涂炭方法优化

Optimization of compound-specific hydrogen isotope analysis of natural gas

涂炭方法对于单体烃氢同位素分析结果有重要影响。分别对正己烷或甲烷进样口注入、甲烷逆向注入3种涂炭方法对氢同位素值测定的影响进行了考察和对比。结果显示,在每次样品分析前采用甲烷逆向注入的涂炭方法,可保证高温裂解炉管中涂炭效果的一致性,使天然气烃类单体化合物氢同位素测定值具有最好的重复性和准确性。

The conditioning method has an important influence on the compound - specific analysis results of hydrogen isotope ratios. The effects of three methods （injection of n-hexane or methane in the inlets, the reverse injection of methane） on the determination of hydrogen isotope values were investigated and compared. The results showed that the method of reverse injection of methane before each sample analysis can ensure the consis-tency of conditioning in the pyrolysis furnace tube, and can provide the best repeatability and accuracy of the compound-specific hydrogen isotope determination of natural gas.