Department of Pesticide Chemistry and Technology, Faculty of Agriculture, Alexandria University, Alexandria, Egypt.
J Environ Sci Health B. 2019;54(11):898-905. doi: 10.1080/03601234.2019.1641389. Epub 2019 Jul 22.
A selective liquid chromatographic analytical method was studied for determination of two neonicotinoids, acetamiprid and imidacloprid, in tomato fruits under greenhouse conditions in Egypt. The fruits were extracted and cleaned up by QuEChERS method followed by HPLC determination. The method showed a good linearity with a determination coefficient () of higher than 0.99 for the 0.0125-0.15 µg/mL concentration range. The method was validated using a blank tomato spiked at 5, 25 and 50 mg/kg and the recovery percentages were 83.71, 94.52 and 97.49% for acetamiprid and 88.59, 89.63 and 90.18% for imidacloprid, respectively. The rates of dissipation of both pesticides were studied and the preharvest intervals (PHIs) were calculated. Imidacloprid dissipated faster than acetamiprid and half-life periods were 1.30 and 2.07 days, respectively. Acetamiprid and imidacloprid residues were below the already established European maximum residue limits (EU MRLs) (0.5 mg/kg) 3 and 5 days after application, respectively.
建立了一种在埃及温室条件下测定番茄中两种新烟碱类杀虫剂——噻虫嗪和吡虫啉的选择性液相色谱分析方法。采用 QuEChERS 方法提取和净化样品，HPLC 检测。该方法在 0.0125-0.15 μg/mL 浓度范围内具有良好的线性关系，相关系数（r）均高于 0.99。采用空白番茄基质分别添加 5、25 和 50 mg/kg 的 2 种农药进行方法验证，噻虫嗪和吡虫啉的回收率分别为 83.71%、94.52%和 97.49%、88.59%、89.63%和 90.18%。研究了 2 种农药的消解动态，计算了其休药期。吡虫啉的消解速度快于噻虫嗪，其半衰期分别为 1.30 和 2.07 天。施药后 3 和 5 天，噻虫嗪和吡虫啉的残留量均低于已建立的欧洲最大残留限量（EU MRLs）（0.5 mg/kg）。
