二氰蒽醌和吡唑醚菌酯在枣中的残留行为及膳食摄入风险评估

Residues and dietary intake risk assessment of dithianon and pyraclostrobin in the jujube

建立了采用高效液相色谱-紫外检测器（HPLC—VWD）检测二氰蒽醌和吡唑醚菌酯在枣中残留量的分析方法，研究了两者在枣中的消解动态、最终残留水平以及膳食摄入风险。样品加盐酸后，用乙腈匀浆提取，Florisil柱净化，HPLC—VWD检测，外标法定量。运用慢性膳食摄入风险（％ADI）和急性膳食摄入风险（％ARfD）对二氰蒽醌和吡唑醚菌酯在不同人群的急（慢）性膳食摄入风险进行了估计。结果表明：在0．1～5mg／kg添加水平下，二氰蒽醌和吡唑醚菌酯在枣中的平均回收率在76％～112％之间，相对标准偏差（RSD）在1．1％～9．6％之间；两种农药在枣中的定量限（LOQ）均为0．1mg／kg。消解动态试验结果表明：二氰蒽醌和吡唑醚菌酯在枣中的消解动态符合一级动力学方程，其消解半衰期分别为1．5～2．5d和12．4～18．4d。最终残留试验结果表明：二氰蒽醌和吡唑醚菌酯在枣中的最终残留量分别为〈0．1～3．83和〈0．1～3．07mg／kg。对2～6、7—14、18—30和60～70岁4类人群进行急（慢）性膳食摄入风险评估结果显示：施药后7d，枣中吡唑醚菌酯的残留量对2～6岁的幼儿存在不可接受的急性膳食摄入风险，其他人群的急（慢）性膳食摄入风险较低；二氰蒽醌在施药后7、14和21d，吡唑醚菌酯在14和21d对4类人群的急（慢）性膳食摄入风险均在可接受范围之内。本研究结果表明：采用16％唑醚·氰蒽醌水分散粒剂防治枣树炭疽病，用药量为2．67∥kg，施药间隔期7d，最大施药次数3次，采收间隔期14d，收获期的枣对各类人群的膳食摄入风险较小。

The objective of this study was to investigate the dissipation dynamics, residue levels and the dietary intake risk of dithianon and pyraclostrobin in the jujube. Dithianon and pyraclostrobin in the jujube were determined by high performance liquid chromatography with ultraviolet detector. The samples were extracted by acetonitrile, and cleaned up by the florisil column. The dietary intake risk for different groups was estimated with %ADI and %ARfD. At the fortified level of 0. 1 to 0. 5 mg/kg, the recoveries of dithianon and pyraclostrobin ranged from 76% to 112% with the relative standard deviations of 1.1% to 9.6%. The limit of quantification （LOQ） of this method was 0. 1 mg/kg. Dissipation dynamic of dithianon and pyraclostrobin in the jujube fitted the fist-order kinetics equation, with half-lives from 1.5 to 2.5 days and from 12. 4 to 18.4 days, respectively. The terminal residues of dithianon and pyraclostrobin were from 〈0. 10 mg/kg to 3.83 mg/kg and from 〈 0. 10 mg/kg to 3.07 mg/kg, respectively. The dietary intake risk assessment for the different groups of people shows that the acute dietary intake risk of pyraclostrobin was unacceptable for the children of 2 -6 years old at the 7^th day after the last application. The dietary intake risk was acceptable in all the other conditions. The security interval of 16% pyraclostrobin.dithianon water dispersible granules was 14 days, when sprayed for 3 times at the dose of 2.67 g/kg for the prevention of anthrax, and the dietary intake of various groups with less risk during the harvest season.