溴虫腈在菜用大豆上残留动态及安全使用技术

采用气相色谱(GC-ECD)及田间试验方法,研究了溴虫腈在菜用大豆中的残留消解动态和安全使用技术。结果表明,溴虫腈在菜用大豆上的原始残留沉积量因不同施药处理而有所差异。其残留消解动态符合一级动力学关系,相关系数(︱r︱)=0.9438-0.9847(P<0.01);早季的消解系数(︱k︱)=0.13555±0.001955,半衰期(T1/2)为5.0-5.2 d,消解99%所需要的时间(T0.99)为33.5-34.5 d;晚季的︱k︱=0.12748±0.00268,T1/2为5.3-5.6 d,T0.99为35.4-36.9 d。按常规施药方法,在菜用大豆上施用溴虫腈(112.50 g.hm-2),在施药1次后17 d,早季豆的农药最终残留量为0.448 mg.kg-1,晚季豆的农药最终残留量为0.519 mg.kg-1;连续施药2次(间隔7 d)后22 d,早季豆的农药最终残留量为0.459 mg.kg-1,晚季豆的农药最终残留量为0.536 mg.kg-1,产品质量安全水平均符合美国规定的最高残留限量标准。

Residual dynamics and safe use technology of chlorfenayr in vegetable soybean

By the methods of GC-ECD and field experiment,the residual degradation dynamics and the safe use technology of chlorfenayr in vegetable soybean were investigated.The result showed the original sediments of chlorfenayr were different in different treatments.The residual degradation dynamics of chlorfenayr in vegetable soybean were in line with the first order kinetic equation,and the correlation coefficient ranged from 0.9438 to 0.9847(P<0.01).In early season,the degradation coefficient of chlorfenayr(︱k︱) was 0.13555±0.001955.The half-life(T1/2) ranged from 5.0 d to 5.2 d and the time of 99% degradating rate(T0.99) ranged from 33.5 d to 34.5 d.In late season,the degradation coefficient of chlorfenayr was 0.12748±0.00268.T1/2 ranged from 5.3 d to 5.6 d and T0.99 ranged from 35.4 d to 36.9 d.According to conventional useable dosage,after spraying with 112.50 g·hm-2 effective constituent of chlorfenayr, 17 days later the last residual contents was 0.448 mg·kg-1for early season vegetable soybean and 0.519 mg·kg-1 for late season vegetable soybean,respectively.While it was sprayed twice at intervals(7 d),after 22 d the last residual content was 0.459 mg·kg-1for early season vegetable soybean and 0.459 mg·kg-1 for late season vegetable soybean,respectively.The quality safety of these products was in line with the demand of MRL(0.1 mg·kg-1) in USA.