Dissipation dynamics of abamectin in cotton and soil

Field trial had been conducted in Jinan and Hefei.An analytical method was developed to determine dynamic of abamectin and final residue in cotton leaf,soil and cottonseed using ultra performance liquid chromatography coupled with electrospray tandem mass spectrometry(UPLC-ESI-MS/MS).The experimental results show that when the samples were spiked with abamectin at 2-50 μg.kg-1 levels,the overall average recoveries for abamectin ranged from 78.2% to 98.0% and the RSDs was 2.6%-6.4%.The degradation rate of abamectin in cotton leaf and soil samples followed the first-order kinetics equation.The half-life of abamectin in cotton leaf was 0.7-0.8 days and in soil was 0.9-1.4 days.The final residues in cottonseed and soil were no detected.So it was safe that cotton was sprayed one time at the recommended dosages of 16.2-24.3 g.hm-2.