苯醚甲环唑在烟叶和土壤中农药残留与降解

Residues and Decline Dynamics of Difenoconazole in Tobacco and Soil

【目的】研究苯醚甲环唑在烟草上的合理安全使用，为农药使用和限量制定提供科学依据。【方法】建立烟叶及其土壤中苯醚甲环唑农药残留的气相色谱检测方法，并测定烟叶及土壤中苯醚甲环唑农药残留降解动态和烤后烟叶中的最终残留量。【结果】苯醚甲环唑在烟叶中降解较快，土壤中相对偏慢，半衰期分别为4．84-7．74、15．20-17．68d，施药后35d，烟叶中农药残留降解率达90％以上，在土壤中的降解率超过80％。苯甲·福美双可湿性粉剂按苯醚甲环唑有效成分150、225ga．i．／hm^2于烟草现蕾期喷雾3-4次，距末次施药后间隔21d采样，烟叶中苯醚甲环唑的残留量为0．86～9．61mg／kg，土壤中的残留量低于0．18mg／kg。

[Aims] It was to provide guidance for safe and reasonable use and MRL of difenoconazole on tobacco. [Methods] The analytical method of difenoconazole and dissipation dynamics in tobacco leaf and soil were investigated, [Results] Results of the decline dynamics study showed that the dissipation in fresh tobacco leaves was faster than in soil, and half-life （t1/2） were 4.84-7.74 d in fresh tobacco leaves and 15.20-17.68 d in soil, respectively. 35 Days after application, the residue remained less than 10% of initialization in fresh tobacco leaves, and less than 20% of initialization in soil. The ultimate residues of difenoconazole in curied tobacco leaves and soil were determined after the third and fourth application at levels of 150 and 225 g a.i./ha, with the residues ranging from 0.86-9.61 mg/kg in tobacco leaves and below 0.18 mg/kg in soil 21 days after the last treatment.