Determination of Thiamethoxam Residue in Cucumber and Soil by HPLC

A method for the determination of thiamethoxam residue in cucumber and soil by high performance liquid chromatography with UV detector was established. The sample was extracted by water/methyl alcohol, reextracted by dichloromethane, cleaned up by Envi-Carb column, eluted by methanol/acetonitrile. The average recovery of method varies from 88.7 to 96.2% and the relative standard deviation was less than 8.6% when the sample was spiked at 0.02 to 2.0 mg/kg. The lowest detection limit for thiamethoxam was 4×10-10 g, and detectable concentration was 0.008 mg/kg in cucumber. The proposed method was characterized by simplicity, higher sensitivity and accuracy.