萎锈灵在大麦和土壤中的残留及安全性评价

Residues and Safety Evaluation of Carboxin in Barley and Soil

为探明萎锈灵在大麦上的残留特性和安全性,通过田间试验和室内检测,研究了萎锈灵在大麦和土壤中残留的检测方法、萎锈灵在土壤中的消解动态及其在大麦和土壤中的最终残留量。结果表明,本检测方法对萎锈灵的最小检出量为0.002ng,萎锈灵在大麦植株、籽粒和土壤中的最低检测浓度分别为0.005、0.002、0.001mg·kg^(-1),添加回收率分别为78.9%~94.0%、92.4%~98.6%和90.6%~101.3%;相对标准偏差分别为1.3%~7.9%、1.8%~4.7%和0.9%~4.8%。萎锈灵在土壤中的半衰期为6.5~7.1d,药后14d消解率大于93%。400g·L^(-1)萎锈·福美双悬浮剂120、180g a.i.·100kg^(-1)种子拌种,收获期大麦籽粒中萎锈灵残留量均低于0.002mg·kg^(-1),说明400g·L^(-1)萎锈·福美双悬浮剂在大麦上使用是安全的。

A field experiment and laboratory testing were conducted to reveal a method for determination of carboxin residues in barley and soil,residual dynamics of carboxin in soil and the final residues of carboxin in barley and soil.The results showed that the limit of detection（LOD）of carboxin is 0.002 ng,and the limit of quantification（LOQ）of carboxin in barley plant,seed and soil were 0.005 mg·kg^-1,0.002 mg·kg^-1 and 0.001 mg·kg^-1,respectively.Recovery rate of carboxin in barley plant,seed and soil were 78.9% to 94.0%,92.4% to 98.6% and 90.6% to 101.3%,respectively.Relative standard deviation（RSD）of carboxin in barley plant and seed and soil were 1.3% to 7.9%,1.8% to 4.7% and 0.9% to 4.8%.The half-life of carboxin in soil were 6.5 to 7.1 d,residue degradation rate in soil at 14 dafter application was above 93%.When the barley seed was dressed with 120 and 180 g a.i·100 kg^-1 seed carboxin and thiram 400 g·L^-1 SC before seeding,the residues of carboxin in the harvested barley was lower than 0.002 mg·kg^-1（maximum residue limit,MRL）.It is safe when carboxin and thiram 400 g·L^-1 SC was applied on barley.