典型挥发性有机化合物在气体采样罐中的存储稳定性

选取了6种有代表性的挥发性有机化合物（VOCs）,异丙醇、二氯甲烷、乙酸乙烯酯、正己烷、苯和四氯化碳,实测了这些VOCs在气体采样罐（SUMMA罐）中的存储稳定性。结果表明：苯、正己烷和二氯甲烷在采样罐中均较稳定,其含量在84 d的存储期内基本无变化;乙酸乙烯酯在6个VOCs中最不稳定,在普通和惰性采样罐中含量均明显下降;异丙醇和四氯化碳的稳定性与采样罐的类型有关,在普通采样罐内含量下降明显,而在惰性采样罐内则相对稳定。实际监测工作中,为提高VOCs分析的准确性,如目标分析物有含氧类（醇,酮,酯等）或含卤素类VOCs,则采样后需尽快分析,同时尽量选择惰性采样罐为采样容器。

Storage stability of representative volatile organic compounds（VOCs）in air sampling canister

Six kinds of representative volatile organic compounds（VOCs）,such as：isopropyl alcohol,methylene chloride,vinyl acetate,hexane,benzene and carbon tetrachloride,were selected to test their storage stabilities in air sampling canisters（SUMMA canisters）. The results show that：Benzene,hexane and methylene chloride are stable in canisters,and their contents are almost unchanged in 84 d of storage period;Vinyl acetate is most unstable in the 6 VOCs,and its content decreases significantly in both traditional SUMMA canister and silicon-lined canister;The stability of isopropyl alcohol and carbon tetrachloride is related to the type of canister,their contents decrease significantly in traditional SUMMA canisters while stable in silicon-lined canisters. For increasing the accuracy of VOCs analysis in actual monitoring,samples should be analyzed as soon as they are collected,especially when oxygen- or halogen- containing compounds（such as alcohols,ketones and esters）are on the target list. Furthermore,silicon-lined canisters are used as sampling containers as far as possible.