GC Determination of Organophosphorus Pesticides in Water with Solid Phase Micro-extraction

GC with sample pretreatment by solid phase micro-extraction(SPME) was applied to the determination of residual amounts of 6 organphosphorus pesticides in water.To attain a higher efficiency for SPME. the 65μm PDMS/DVB micro-extractor was selected,and the extraction was carried out at 80℃for 20 min.with addition of 1.5 g NaCl to 10 rnL of sample solution as salting out agent.The analyte were separated on HP-5 capillary column and detected by ECD.Linear relationships between values of peak area and mass concentration of the 6 organphosphorus pesticides were kept in the same range of 1.0—50.0μg ? L~(-1),with detection limit(3S/N) in the range of 0.026—0.064μg ? L~(-1).The proposed method was applied to the analysis of water samples,giving values of recovery found by standard addition method in the range of 86.2%—115.7%with RSD's(n=6) in the range of 3.0%-5.6%.