Institute for Agri-Food Standards and Testing Technology, Shanghai Academy of Agricultural Science, Shanghai 201403, China.
Shanghai Service Platform of Agro-Products Quality and Safety Evaluation Technology, Shanghai 201403, China.
Molecules. 2021 Oct 27;26(21):6495. doi: 10.3390/molecules26216495.
Multiple insecticides' residues after the mixed application of several neonicotinoids cause combined pollution and bring new challenges to food safety and pest control during agricultural production. In this study, three neonicotinoid insecticides, namely imidacloprid (IMI), acetamiprid (ACE), and thiamethoxam (TMX), were mixed and evenly sprayed on L. in the field. Then, the insecticides' residues were dynamically monitored to determine the differences in their rates of dissipation and final residues after 10 days. The results showed that the dissipation kinetics of neonicotinoids still conformed to the first-order kinetic model for binary or ternary application of neonicotinoid mixtures, with all determination coefficients (R) being above 0.9 and the dissipation half-life (DT) being 2.87-6.74 d. For treatment groups with five times the recommended dosages (IMI 300 g·hm, ACE 900 g·hm, and TMX 600 g·hm), mixed insecticides had a slower dissipation rate, and the DT values of mixtures were longer than those of single insecticides. Moreover, the final insecticide residues with mixed application were higher than those of single compounds at 10 d after spraying. Thus, mixed applications of neonicotinoids may increase food safety risks as they increase the final insecticide residues in L., and care should therefore be taken when considering the combined use of such compounds.
多种新烟碱类杀虫剂混合使用后会产生残留的复合污染，给农业生产中的食品安全和害虫防治带来新的挑战。本研究在田间均匀喷施三种新烟碱类杀虫剂（吡虫啉、噻虫胺和噻虫嗪），动态监测其残留量，以确定 10 天后其消解速率和最终残留量的差异。结果表明，新烟碱类杀虫剂的消解动力学仍符合二元或三元新烟碱类混合物的一级动力学模型，所有决定系数（R）均大于 0.9，消解半衰期（DT）为 2.87-6.74 d。对于推荐剂量五倍的处理组（吡虫啉 300 g·hm-2、噻虫胺 900 g·hm-2 和噻虫嗪 600 g·hm-2），混合杀虫剂的消解速度较慢，混合物的 DT 值长于单一杀虫剂。此外，混合使用后 10 d 的最终农药残留量高于单一化合物。因此，新烟碱类杀虫剂的混合使用可能会增加食品安全风险，因为它们会增加 L.中的最终农药残留量，因此在考虑这些化合物的联合使用时应谨慎。
