Persistence and Residue of Clomazone in Soil and Soybean by HPLC-DAD

摘要

Recent concerns of ground and surface water contamination by some of the herbicides has lead to renewed interest on persistence and degradation behaviour of herbicides in soil environment. Thus, this study was conducted to assess the persistence and residue of clomazone in soil and soybean. The clomazone residue was extracted using methanol- water and determined by Agilent HPLC-DAD. The clomazone recovery from different matrices varied from 84 to 103 %, at fortification levels of 1 to 0.1 μg g~(-1). More than 80 % of the applied clomazone degraded from soil within 14 days with mean half life of 4.9 days. Clomazone residues were found above the detection limit in soil and soybean only when it is applied at higher doses (1250 and 2000 g a.i. ha~(-1)) No clomazone residues (< 0.01 mg/kg) were detected in any of the matrices at the lower concentrations of 750 and 1000 g a.i. ha~(-1) treatments. On the basis of clomazone persistence in soil and grain, a safe pre-harvest interval of 95 days for soybean after clomazone application is suggested.