Development and Validation of Analytical Method for Pesticide Multi-Residue in Soil and Water Using GC-ECD/NPD

Abstract

It needs to safety control for agricultural soil, water that directly effect on producing and safety of crops. This research developed pesticide multiresidue analysis method based on NAQS for 166 pesticides (GC-ECD : group1 26, group2 23, group3 24, group4 24, GC-NPD group 1 18, group2 18, group3 17, group4 16 compounds) and validated method according to KOLAS guideline. On developing method, extraction, wetting and purification steps were optimized. Compared acetonitrile, dichloromethane, ethyl acetate as extraction solvent and the result of acetonitrile was best. In extraction of soil sample, NaCl 20g was changed to saturated brine 30 mL. Water sample was only filtrated, without purification. Developed method was applied to 3 soil samples (paddy, field, and orchard) and 4 water sample (distilled water, river, underground water and lake) and tested 7 times. From this date, validation parameters on KOLAS guideline (linearity, precision, trueness & bias, method LOD/LOQ, sensitivity, selectivity, working range, ruggedness) were calculated. Measurement uncertainty was estimated from monitoring sample collected in whole country. Endosulfan sulfate was used for GC-ECD and its measurement uncertainty was 1.662 ± 0.121 μg/kg (k=2.042) and chlorpyrifos(GC-NPD) was 0.0076 ± 0.0011 μg/kg (k=2.086)