虱螨脲在棉花和土壤中的残留动态

在长沙和郑州2地进行田间试验,采用液相色谱技术研究虱螨脲在棉籽、棉叶及土壤中的残留动态.结果表明:虱螨脲在棉叶、棉籽和土壤中的添加回收率分别为86.0%～94.7%、88.5%～92.1%和83.9%～97.7%;最低检出浓度分别为0.025、0.025和0.006 mg·kg-1.虱螨脲在棉叶和土壤中的半衰期分别是3.06～3.45和2.51～2.88 d.在推荐使用剂量和高剂量条件下,收获的棉籽中虱螨脲最终残留量均未检出,拟推荐我国棉籽中虱螨脲的MRL(最高残留限量)值为0.05 mg·kg-1.

Residues and Degradation of Lufenuron in Cotton and Soil

Field experiments were carried out in Changsha and Zhengzhou to determine residue and degradation dynamics of lufenuron in cotton leaves,cotton seeds and soil.Results show that its recovery rate was in the range of 86.0%-94.7%,88.5%-92.1% and 83.9%-97.7%,and its minimum detectable concentration was 0.025,0.025 and 0.006 mg·kg-1,respectively.And its half-life was 3.06-3.45 days in cotton leaves and 2.51-2.88 days in soil.In the cotton seeds harvested from fields applied with a recommended dose and a high experimental dose,respectively,its final residue was undetectable.The recommended MRL for lufenuron in cotton seed is 0.05 mg·kg-1 in China.