40％丙硫菌唑·戊唑醇悬浮剂在小麦上的残留行为和膳食风险评估OA

To evaluate the safety of prothioconazole·tebuconazole 40％suspension concentrate(SC)in wheat,the degradation dynamics of the two active ingredients in wheat grains were investigated at four test sites,and the final residues in wheat grains and straws were determined at twelve test sites.A QuEChERS-ultra performance liquid chromatography tandem mass spectrometry(UPLC MS/MS)analytical method was established.The results showed that the average recoveries of prothioconazole and tebuconazole in wheat grain and straw at four spiked levels ranged from 81％to 107％,with relative standard deviations of 0.4％～4.1％.The degradation of both compounds in wheat grains followed first order kinetics,with half lives of 12.8～28.9 d for prothioconazole and 6.5～10.8 d for tebuconazole.The formulation was applied twice at an interval of 7 days at an active ingredient dosage of 210g/hm2.At 35 and 42 days after the last application,the final residues in all regions were below the maximum residue limits(MRL)specified in national standards,and the safety interval was determined to be 35 days.The total dietary risk quotients were 3.91％and 66.07％,respectively,indicating that the dietary risk associated with the use of 40％prothioconazole·tebuconazole SC in wheat is acceptable for the general population.