Chiang Mai Journal of Science

Eight organochlorine pesticides in sediment were extracted twice, each with 20 ml diethylether for 30 min with the percentage recoveries in the ranges of 84.91-98.71. The detection limits for extraction of organochlorine in sediment were in the ranges of 0.32-0.90 ng/g. The soxhlet extraction was the method for removal of carbamate pesticides from sediment. The mixture of methanol–dichloromethane–acetone (1:1:1) was the suitable extracting solvent with the extraction time of 16 hours. The detection limits for extraction of carbamate pesticides in sediment were in the ranges of 2.1-3.1 ng/g. The results showed good percentage recoveries in the ranges of 81.35 - 96.49. These procedures were successfully applied to analysis of pesticides in 5 sediment samples.