吹扫捕集-气相色谱-质谱法测定地下水中的挥发性有机物

Determination of Volatile Organic Compounds in Groundwater by GC-MS with Purge and Trap Sampling

采用吹扫捕集-气相色谱-质谱联用技术,建立了适用于地下水中卤代烃、氯代苯和苯系物等27种挥发性有机污染物的分析方法。水样经吹扫捕集后,待测物在Rtx-5MS毛细管色谱柱上分离,质谱分析中采用电子轰击离子源和选择离子监测模式,内标法定量。考察了不同解析时间、不同分流比以及固定剂盐酸对测定的影响。27种挥发性有机物的线性范围均为0.4~40μg·L^(-1),检出限(3s)在0.10~0.32μg·L^(-1)之间。加标回收率在91.6%~111%之间,测定值的相对标准偏差(n=7)在1.3%~8.8%之间。

A method based on GC-MS combined with purge and trap sampling was developed for the determination of 27 volatile organic compounds（VOCs）including halohydrocarbons,benzene series,chlorobenzene compounds and etc.in groundwater.After purge and trap sampling,the analytes were separated on an Rtx-5MS capillary column.EI,SIM and the internal standard method were used in MS analysis.The effect of desorption time,split ratio and HCl fixatives on the determination results were investigated.The linear ranges of 27 VOCs were 0.4-40μg·L-1,with detection limits（3s）in the range of 0.10-0.32μg·L-1.Recovery rates obtained by standard addition method were in the range of 91.6%- 111%,and RSDs（n=7）were in the range of 1.3%-8.8%.