溴氰菊酯在茼蒿和土壤中的残留动态及安全性评价

Residue Dynamics and Safety Evaluation of Deltamethrin in Crown Daisy and Soil

[目的]探讨溴氰菊酯在茼蒿上的残留特性和安全风险。[方法]通过田间试验和室内检测研究溴氰菊酯在茼蒿及土壤中的残留动态及最终残留量。[结果]溴氰菊酯在茼蒿中的半衰期为3.9~4.5 d,药后14 d消解92%以上。溴氰菊酯在土壤中的半衰期为6.5~7.4 d,药后14 d消解79%以上。25 g/L溴氰菊酯乳油18.750、28.125 g a.i./hm^2,施药3、4次,末次施药后5 d收获的茼蒿中溴氰菊酯残留量均低于2 mg/kg。推荐溴氰菊酯在茼蒿上的安全间隔期为5 d。[结论]试验结果为溴氰菊酯在茼蒿上的安全合理使用及制定溴氰菊酯在茼蒿上的最大残留限量国家标准提供了理论依据。

[Objective] To research the residual characteristics and safety risk of deltamethrin in crown daisy.[Method] Field experiment and la-boratory testing were conducted to reveal residual degradation dynamics and the final residues of deltamethrin in crown daisy and soil .[Result] The half-life of deltamethrin in crown daisy and soil were 3.9-4.5 d and 6.5-7.4 d,respectively.Residue degradation rate in crown daisy at 14 d after application was above 92%,and it was above 79%in soil at 14 d after application.When the crown daisy was sprayed 3 to 4 times with 18.750 and 28.125 g a.i./hm^2 of 25 g/L deltamethrin EC,the last application was done 5 d before harvesting,the residue of deltamethrin in the harvested crown daisy was lower than 2 mg/kg （MRL）.It was demonstrated that the preharvest interval of deltamethrin on crown daisy was 5 d. [Conclusion] The research results provide scientific basis for the rational and safe use of deltamethrin in crown daisy,and for the establishment of maximum residue limits （ national standard） of deltamethrin in crown daisy .