GC Determination of Organochlorine Pesticides and Polychloro-Biphenyls in Water with Enrichment by Liquid-Liquid Extraction

GC chromatography with electron capture detector was applied to the determination of organochlorine pesticides (OCP′s) and polychloro-biphenyls (PCB′s) in water. OCP′s and PCB′s were separated and enriched from water sample by extraction with n-hexane. The extract was concentrated to about 0.5 mL and diluted to 1.0 mL with n-hexane. The double caplillary chromatographic column technique, i.e. use of 2 columns of different polarity (the Rtx-5MS column and the Rtx-1701 column) was adopted in separation and identification of the OCP′s and PCB′s was performed by comparing values of tR of sample with that of standard samples, and quantification was performed by using the external standard method with the Rtx-5MS column. Linear relationships between values of peak area and mass concentration of the OCP′s and PCB′s were found same in the range of 0.5-40 μg·L-1, with detection limits (3s) in the range of 0.001 1-0.004 7 μg·L-1. Recovery of the method was tested giving values of average recovery ranged form 83.3% to 112.1% and RSD′s (n=7) ranged from 4.4% to 9.4%.