Abstract
BACKGROUND: The purpose of this study was to investigate the effects of clothianidin on the soil in terms of clothianidin dissipation and degradation to evaluate its safety in order to provide an analytical foundation for clothianidin and the 5 metabolites related to it. METHODS AND RESULTS: High-performance liquid chromatography(HPLC) was used to separate clothianidin and its metabolites in this study. In soil, after suppressing dissociation-proned ions with weak alkalic $NH_4OH$ and extracting the metabolites with methanol, clothianidin, Methylaminoimidazole(MAI), Methylnitroguanidine(MNG), Thiazolylmethylurea(TZMU) and Thiazolylnitroguanidine(TZNG). Thiazolylmethylguanidine(TMG) were extracted with the addition of neutral $NH_4OAC$ to increasing the intensity of ions. Compounding elements were separated by using Hydrometrix ($ChemElut^{TM}$) and ion-exchanging Solid-phase extraction(SPE) Strong cation-exchanger(SCX) and C18 were used. The recovery rates of clothianidin and 5 metabolites in soil and water ranged from 87.4% to 104.3%. A standard deviation of our analysis for the soil and water samples were less than 5%. CONCLUSION: Well accepted detection limits for clothianidin and 5 metabolites in soil samples based on a dissipation analysis is 0.005 mg/kg and 0.001 mg/L in water samples. The dissipation concentration of this study was decided to be enough to evaluate the dissipation levels of clothianidin and its metabolites.
