The Storage Stability Experiment Study Of Bensulfuron-methyl And Butralin WP In Paddy Samples

With the increasing using amount of pesticides, people focus more attention on the safety of foods, environmental and agricultural products. The analysis could not timely processing of large amounts of pesticide residue samples, residue during the storage period maybe change. This might influence the accuracy of the determination,and caused the influence accurate assessment of the pesticide. Hence the research on storage stability of pesticide residues was very essential.In this paper, a method has been developed for determining bensulfuron-methyl and butralin residues in paddy samples by high performance liquid chromatography(HPLC). And their storage stability under different conditions(-18℃ and-20℃) was investigated in paddy samples(paddy soil、paddy water、rice plant、brown rice and rice husk). The samples were taken in different periods, extracted with acetonitrile, purified by Florisil-phase and Alumina N-neutral(SPE) and using dichloromethane:methanol=7:3(v/v) mixed eluent leaching. HPLC analysis of bensulfuron-methyl and butralin was detected at 240 nm. The operating conditions were mobile phase(gradient elution) acetonitrile/pure water(v/v). The calibration curves have good linear correlation in the concentration range of 0.1-5.0 mg·kg-1 for both pesticides(0.9997 and 0.9999). The average recovery rates were 73.0%-106.4%, the standard deviation were 0.5%-12.0%, respectively. Bensulfuron-methyl and butralin are stability when stored in 5 paddy matrix(paddy soil, paddy water, rice plant, brown rice and chaff) for 180 days. Their degradation rates were less than 5% and conformed to FAO/WHO Standards equivalent identification requirements. The good stability of bensulfuron-methyl and butralin was achieved.An analytical method was developed for the determination of bensulfuron-methyl and butralin in paddy samples by high performance liquid chromatography(HPLC). The studies show that this method is more efficient and quick, the extent of sensitivity and accuracy of the residual determination in paddy samples of bensulfuron-methyl and butralin all meet the requirement of pesticide residue determination. The storage stability of bensulfuron-methyl and butralin were determinated in paddy samples. This method can also be set up to relevant departments for the similar research to provide reference for sample storage。...