易保在苹果和土壤中的残留动态研究

Residue Dynamics of Famoxadone in Apple and Soil

在北京市海淀区进行了易保68.75%水分散粒剂在苹果上的残留动态和最终残留试验,用HPLC测定了其有效成分恶唑菌酮的残留量。恶唑菌酮的最低检出量为2.0×10-10g,在苹果中的最低检出浓度为0.004 mg.kg-1,在土壤中的最低检出浓度为0.002 mg.kg-1。在苹果中的平均回收率为91.5%~92.3%,变异系数为0.13%~3.18%,在土壤中的平均回收率为89.7%~100.6%,变异系数为2.10%~10.10%,符合农药残留分析的要求。结果表明,恶唑菌酮在苹果上的半衰期为11.6 d,在土壤中的半衰期为6.8 d。按推荐剂量和推荐剂量的两倍施用的情况下,恶唑菌酮在苹果中的残留量为0.048~0.406 mg.kg-1,土壤中的残留量为0.057~0.539 mg.kg-1,均低于最大残留限量。

Residual dynamics and final residue of famoxadone in apple and soil were studied by HPLC.Residues of famoxadone were extracted from apple and soil with menthol,concentrated and determined by HPLC with UV detector.The lowest detection limit of instrument for famoxadone was 2.0×10^(-10)g,and the limits of quantification in apple and soil were 0.004 and(0.002) mg·kg^(-1) respectively.The average recovery was 89.7%~100.6%,and coefficient of variation was 0.13%~10.10%,respectively.The half-lives of famoxadone in apple and soil were 11.6 days and 6.8 days,respectively.When applied as foliage spray at the rates of recommended dosage and the twice-recommended dosage,the final residue of famoxadone ranged from(0.048)~0.406 mg·kg^(-1)and 0.057~0.539 mg·kg^(-1)in apple and soil respectively,and did not exceed the maximum residue limit 2 mg·kg^(-1) established by EU.According to the results,we recommend that 68.75% Equation contact water-dispersible granule(WG) was applied in apple as foliage spray three times at a dosage of 1 000 dilution factor with a safe interval of 28 days from harvest.