Beijing Academy of Agricultural and Forestry Science, Institute of Plant and Environmental Protection, Beijing, 100097, People's Republic of China.
Institute for the Control of Agrochemicals, Ministry of Agriculture and Rural Areas, Beijing, 100125, People's Republic of China.
Environ Sci Pollut Res Int. 2021 Feb;28(7):8844-8852. doi: 10.1007/s11356-020-11164-6. Epub 2020 Oct 19.
The dissipation and residue levels of thiamethoxam and its metabolite clothianidin in cowpea were investigated under field conditions. Samples of cowpea were analyzed using a QuEChERS technique with ultra-performance liquid chromatography tandem mass spectrometry. The recoveries were 86.5-118.9% for thiamethoxam and 75.6-104.1% for clothianidin, with the coefficient of variation of < 13%. The water dispersible granule formulation of thiamethoxam was applied on cowpea at 30 and 45 g active ingredient ha in accordance with good agricultural practice. The half-life of thiamethoxam in cowpea was 0.8-1.6 days. The cowpea samples were gathered at 3, 7, and 10 days after the last application, and the residues of thiamethoxam in cowpea were < 0.005-0.054 mg kg, while those of clothianidin were < 0.005-0.008 mg kg. The final residues of thiamethoxam and clothianidin were below the European Union (EU) maximum residue level (0.3 mg kg for thiamethoxam; 0.2 mg kg for clothianidin) in cowpea after a preharvest interval (PHI) of 7 days. This study provided basic data on the use and safety of thiamethoxam and clothianidin in cowpea to help the Chinese government formulate a maximum residue level for thiamethoxam in cowpea.
在田间条件下研究了噻虫嗪及其代谢物噻虫胺在豇豆中的消解和残留水平。采用 QuEChERS 技术结合超高效液相色谱-串联质谱法对豇豆样品进行分析。噻虫嗪和噻虫胺的回收率分别为 86.5-118.9%和 75.6-104.1%，变异系数<13%。噻虫嗪水分散粒剂按良好农业规范在豇豆上施用量为 30 和 45 g 有效成分/公顷。噻虫嗪在豇豆中的半衰期为 0.8-1.6 天。最后一次施药后 3、7 和 10 天采集豇豆样品，噻虫嗪在豇豆中的残留量<0.005-0.054 mg/kg，噻虫胺的残留量<0.005-0.008 mg/kg。在 7 天的休药期后，噻虫嗪和噻虫胺在豇豆中的最终残留量低于欧盟（EU）最大残留限量（噻虫嗪 0.3 mg/kg；噻虫胺 0.2 mg/kg）。本研究为噻虫嗪和噻虫胺在豇豆中的使用和安全性提供了基础数据，有助于中国政府制定噻虫嗪在豇豆中的最大残留限量。
