阿维菌素在棉花和土壤中的消解规律研究

Dissipation dynamics of abamectin in cotton and soil

在济南和合肥开展了阿维菌素在棉花和土壤中残留田间试验,采用超高效液相色谱-质谱联用分析方法,研究了阿维菌素在棉花和土壤中的消解动态和最终残留。试验结果表明:阿维菌素在添加浓度水平为2～50μg·kg-1,平均回收率为78.2%～98.0%,相对标准偏差(RSD)为2.6%～6.4%;阿维菌素在棉叶和土壤中的消解动态符合一级动力学方程,其在棉叶中的半衰期为0.7～0.8 d,在土壤中的半衰期为0.9～1.4 d;阿维菌素在棉籽和土壤中的最终残留量均为未检出。建议按照按推荐剂量16.2～24.3 g·hm-2施药,施药1次,其在棉籽中的残留是安全的。

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.