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

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 0.4-40 μg·L-1, with detection limits (3s) in the range of 0.10-0.32 μg·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%.