Residue behavior and dietary exposure risk assessment of metrafenone and ethirimol in cucumber
[Aims]The residue dissipation and intake risk assessment of metrafenone and ethirimol in cucumber were conducted,to evaluate the safety of metrafenone and ethirimol used in cucumber.[Methods]The supervised residual trials of metrafenone and ethirimol in cucumber were carried out in 12 typical regions.A rapid and simple analytical method for determination of metrafenone and ethirimol residues in cucumber using UPLC-MS/MS was developed.The final residues and dissipation dynamics were studied,and the dietary intake risks of the two pesticides to Chinese populations were evaluated.[Results]There was a good linear relationship between the concentration and peak area of metrafenone and ethirimol in the range of 0.001-1.0 mg/L(R2≥0.99).At the spiking levels of 0.01-20.0 mg/kg,the average recoveries of metrafenone and ethirimol in cucumber samples were 76％-87％and 75％-89％,with the relative standard deviation(RSD)ranged from 1.7％to 8.8％and 2.3％to 4.7％,respectively.The limits of quantification(LOQs)of the two analytes in cucumber were all 0.01 mg/kg.The half-lives of metrafenone and ethirimol in cucumber were 2.6-6.3 and 2.6-5.9 d,respectively.When the interval to harvest was 2 d,the supervised trial median residues(STMR)of metrafenone and ethirimol in cucumber were 0.029 and 0.066 mg/kg,and the highest residues(HR)were 0.13 and 0.24 mg/kg,respectively.The chronic dietary exposure risk quotient(RQJ of residues of metrafenone and ethirimol in cucumbers were 0.03％and 0.8％,respectively,which indicated that the chronic dietary exposure risk of metrafenone and ethirimol in cucumber to the general population in China was very low.[Conclusions]Based on the supervised residue trials,metrafenone and ethirimol are safe to general population when applied strictly in accordance with the Good Agricultural Practices and label recommendations on cucumber.
万方数据
维普
