GC Determination of 11 Chlorobenzene Compounds in Soil with Accelerated Solvent Extraction

The freeze-dried sample was extracted by accelerated solvent extraction with n-hexane, and then the extract was concentrated (dry process). The fresh sample was extracted by accelerated solvent extraction with the mixture of n-hexane and acetone (volume ratio:1:1); the extract was dehydrated and purified by magnesium silicate column; then the eluent was collected and concentrated (wet process). GC was applied to the determination of 11 chlorobenzene compounds in the above concentrated solution. The analytes were separated on Agilent DB-1701 capillary chromatographic column and detected by ECD. Linear relationships between values of peak area and mass concentration of the 11 chlorobenzene compounds were kept in definite ranges. Detection limits (3.143s) of the method ranged from 0.002 to 0.030 mg·kg^-1. The proposed method was applied to the analysis of the soil samples prepared by dry process and wet process, giving values of recovery found by standard addition method and RSDs (n=6) of determined values in the ranges of 45.3%-140% and 2.7%-24% respectively.