Abstract:This study optimized the traditional liquid-liquid extraction method and the detection conditions of the hexane extraction-gas chromatography(HE-GC)method, and developed a method for simultaneously determining five types of volatile chlorinated hydrocarbons(VCHs), including tetrachloroethylene, trichloroethylene, carbon tetrachloride, chloroform, and 1, 2-dichloroethane in groundwater. The results show that the highest extraction efficiency can be achieved with a hexane-to-sample volume ratio of 5∶1 after three minutes of vortex rotation. The optimization results show that the detection limits for tetrachloroethylene, trichloroethylene, carbon tetrachloride, chloroform, and 1, 2-dichloroethane were 2. 6, 3. 0, 2. 5, 3. 8, and 35. 9 μg/L, respectively. The recovery rates of the five types of VCHs in blank samples with standard solutions added were between 97. 3% and 114. 6%. The recovery rates for low- and high-concentration samples ranged from 90. 8% to 113. 3%, and from 107. 4% to 114. 5%, respectively. The optimized method has shortened the time of extraction compared with the traditional method and improved the efficiency of pollutant recovery. The detected concentrations of the five types of VCHs in groundwater samples collected from a representative site using the optimized method were consistent with those using the purge-and-trap gas chromatography method.