To determine the residue risks of fluopyram and pyraclostrobin on grapes,the supervised residue trials were conducted in 10 regions within 1 year.A highly efficient and simple method was developed for the determination of fluopyram and pyraclostrobin in grapes using high-performance liquid chromatography(HPLC).The results demonstrated that a good linear relationship between the peak area and the concentration of fluopyram and pyraclostrobin was observed in the range of 0.1-20.0 mg·L-1 with a correlation coefficient greater than 0.99.The average recoveries of fluopyram and pyraclostrobin in grapes at three spiked levels of 0.05,0.50,and 2.00 mg·kg-1 were 88.1%-112.3%and 90.5%-101.5%,with the relative standard deviations(RSDs)ranged from 3.1%-8.2%and 3.5%-9.1%,respectively.The limits of quantification(LOQs)of the two analytes in grape were all 0.05 mg·kg-1.The supervised trial median residues(STMR)of fluopyram and pyraclostrobin in grapes were 0.16 and 0.12 mg·kg-1,and the highest residues(HR)were 1.44 and 1.48 mg·kg-1,respectively,at 14 d after the last application.According to the dietary risk assessment,the contribution rates of fluopyram and pyraclostrobin in grapes to the long-term dietary risk of the general population were 0.142%and 0.036%,the short-term dietary intake risk quotients were 7.8%and 5.7%,and the short-term dietary intake risk quotients for children aged 1-6 years were 19.6%and 14.4%,respectively.These results show that the residues of fluopyram and pyraclostrobin in grapes would not pose significant health risks to children aged 1-6 years and the general population when fluopyram and pyraclostrobin formulation are applied at the recommended dose.
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