香料烟中“溴氰菊酯”的残留降解研究

Study on Residue and Degradation of Deltamethrin in Oriental Tobacco

为了评价"溴氰菊酯"在香料烟中的残留降解行为,进行了连续2年"溴氰菊酯"在香料烟中的残留田间试验。检测结果表明:①2.5%"溴氰菊酯"乳油在香料烟叶中的降解符合一级动力学降解模式,其半衰期为5.80～6.19 d;②施药后15 d残留量在0.0128 mg.kg-1以下,降解率达95%以上;③按600 mL.hm-2喷施2次和3次2.5%"溴氰菊酯"乳油,15 d后采收,香料烟鲜烟叶中的残留量为<0.01～0.4703 mg.kg-1;④2年的气候条件虽然有差异,但"溴氰菊酯"在香料烟中的残留降解行为基本一致。在香料烟的生长过程中,按照推荐用量,在15 d安全间隔期以上,连续3次施用2.5%"溴氰菊酯"乳油,"溴氰菊酯"的残留量不超过0.05 mg.kg-1。

In order to assess the degradation behavior of deltamethrin residues in oriental tobacco,the field experiments were conducted for two consecutive years with 2.5% deltamethrin EC.The test results indicated that： 1） The degradation of deltamethrin EC in oriental tobacco accorded with first level dynamics degradation model,its half-life period was of 5.80 to 6.19 days.2） The residues of deltamethrin in oriental tobacco were below 0.0128 mg/kg 15 days after spraying,and the degradation rate was higher than 95%.3） The residues of deltamethrin in green leaf harvested on 15th day after spraying deltamethrin at a rate of 600 mL/ha（the recommended rate） for 2 or 3 times ranged from 0.01 to 0.4703 mg/kg.4） The degradation behavior was basically unchanged,though the climate conditions were different in the two years.It was concluded that the residues of deltamethrin in oriental tobacco would be below 0.05 mg/kg if it was repeated applied for 3 times at the recommended rate and at an interval of over 15 days.