玉米中丁香菌酯和戊唑醇残留分析及膳食风险评估

Residue analysis and dietary risk assessment of coumoxystrobin and tebuconazole in corn

[目的]研究同时测定玉米中丁香菌酯和戊唑醇的检测方法,分析农药残留,评估膳食风险。[方法]建立QuEChERS-UPLC-MS/MS测定方法,设计10地田间试验用以分析2种农药消解动态和最终残留,计算城、村不同年龄段人群国家估算每日摄入量和风险指数。[结果]方法验证结果表明:2种农药标准曲线相关系数均>0.99,回收率均在70%~120%之间,RSD值均<10%,最低检测质量分数为0.005 mg/kg。消解动态试验结果表明,辽宁和山东玉米植株中丁香菌酯半衰期分别为3.2、3.5 d,戊唑醇的半衰期分别是2.6、2.7 d。最终残留试验表明,安全间隔期40 d,10地玉米籽粒中丁香菌酯和戊唑醇最终残留量均<0.005 mg/kg。膳食风险评估结果表明,丁香菌酯和戊唑醇在玉米中的残留风险处于安全水平。[结论]该前处理和检测方法具有较高准确性、灵敏度和精密度,在玉米上按推荐方法正确使用无残留及膳食风险。

[Aims] This study aims to establish an analytical method for residue analysis of coumoxystrobin and tebuconazole in corn, and further to assess the dietary risk. [Methods] A method for determination of QuEChERSUPLC-MS/MS was established, ten field experiments were designed to analyze the degradation dynamics and final residues of two pesticides, national estimated daily intake and risk index of different age groups in urban and rural areas were calculated. [Results] The correlation coefficient of standard curves of two pesticides>0.99, the recoveries were between 70% and 120%, RSD<10%, the lowest detection concentration was 0.005 mg/kg. The results of degradation dynamics test showed that the half-lives of coumoxystrobin in the corn plant were 3.2 and 3.5 d, and the half-lives of tebuconazole were 2.6 and 2.7 d in Liaoning and Shandong, respectively. The final residues of coumoxystrobin and tebuconazole of corn kernel were less than 0.005 mg/kg in ten locations after a safe interval of 40 days. The results of dietary risk assessment showed the residual risk of coumoxystrobin and tebuconazole was at a safe level in corn.[Conclusions] The pre-processing and the detection method have high accuracy, sensitivity and precision, there were no residues and dietary risks if used correctly according to recommended methods in corn.