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目的:建立丹参中吡虫啉和多杀菌素的检测方法,并对残留动态情况进行对比研究。方法:样品用有机溶剂提取,利用固相萃取小柱净化,HPLC-DAD进行检测。结果:2种农药残留的前处理均采用固相萃取法,净化较为彻底,检测方法灵敏度高,重复性好,准确度、精密度和检出限均符合农残测定要求。消解动态数据的拟合结果表明,以2 h残留量为初始残留量,吡虫啉和多杀菌素半衰期(t1/2)分别为3.65 d和1.64 d,表明施药初期多杀菌素消解速度比吡虫啉快;1 d后吡虫啉和多杀菌素在丹参中的消解曲线符合一级动力学方程,t1/2分别为6.93 d和11.55 d,表明多杀菌素的持效期更长;在相同剂量标准下,多杀菌素的残留量均低于吡虫啉,因此多杀菌素的安全间隔期比吡虫啉更短。吡虫啉在土壤和产品中的最终残留分别为0.02,0.18 mg·kg-1,多杀菌素均未检出(<1.9μg·kg-1),表明多杀菌素的最终残留更低。结论:在丹参种植中,多杀菌素可作为一种替代吡虫啉的理想农药。
Objective: To establish a method for the determination of imidacloprid and spinosad in Salvia miltiorrhiza.METHODS: Methods: The samples were extracted with organic solvents and purified by solid-phase extraction cartridges and detected by HPLC-DAD. Results: The two kinds of pesticide residues were pretreated by solid phase extraction (SPE). The purification was more thorough. The detection method was highly sensitive and reproducible. The accuracy, precision and detection limits were in line with the requirements of pesticide residues determination. The fitting results of dynamic data of digestion showed that the half-lives of imidacloprid and spinosad (t1 / 2) were 3.65 d and 1.64 d, respectively, at the initial residue of 2 h, indicating that spinosad was digested faster than imidacloprid ; After 1 d, the digestion curves of imidacloprid and spinosad in Salvia miltiorrhiza accord with the first-order kinetic equation with t1 / 2 of 6.93 d and 11.55 d, respectively, indicating that spinosad has a longer persistence period; at the same dose standard, Residual spinosad residues were lower than imidacloprid, so spinosad safety interval shorter than imidacloprid. The final residues of imidacloprid in soils and products were 0.02 and 0.18 mg · kg-1, respectively, and none of the spinosad was detected (<1.9 μg · kg-1), indicating that the final residue of spinosad was lower. Conclusion: Spinach can be used as an ideal pesticide to replace imidacloprid in Salvia miltiorrhiza planting.