GC Determination of 11 Chlorobenzenes in Drinking Water with Dispersive Liquid-Liquid Microextraction Assisted by Vortex

The drinking water sample (10.0 mL) was taken, and then sodium chloride (0.5 g) and carbon disulfide (100 μL) were added. The above mixture was centrifugated for 5 min at the speed of 2 500 r·min^-1. After standing for 5 min, the sedimentation at the bottom of centrifugal tube (about 65 μL) was taken. GC was applied to the determination of 11 chlorobenzenes in the sedimentation. 11 chlorobenzenes were separated on Agilent J&W DB-WAX capillary chromatographic column and detected by ECD. Linear relationships between values of peak area and mass concentration of the 11 chlorobenzenes were kept in definite ranges. Detection limits (3S/N) of the method ranged from 0.032 to 0.97 μg·L^-1. On the base of blank sample, test for recovery was made by standard addition method; values of recovery found were in the range of 86.7%-101%, with RSDs (n=6) of determined values in the range of 1.2%-3.3%.