Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, Shandong Agricultural University, Tai'an, Shandong, 271018, PR China; College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong, 271018, PR China.
Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, Shandong Agricultural University, Tai'an, Shandong, 271018, PR China; College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong, 271018, PR China.
Ecotoxicol Environ Saf. 2019 Oct 30;182:109445. doi: 10.1016/j.ecoenv.2019.109445. Epub 2019 Jul 19.
In this study, a new, high-efficiency and sensitive method was determined to simultaneous analyze the residue of pyraclostrobin, picoxystrobin and its metabolite BF-500-3 in pepper fruit using modified QuEChERS pretreatment combined with ultra performance liquid chromatography-tandem mass spectrometry. The clean-up steps of QuEChERS procedure were optimized using the chemometric tools. Models of stepwise regression and surface response demonstrated that the optimal sorbent mixtures were 40 mg nano-zirconia + 10 mg C for pyraclostrobin and picoxystrobin and 30 mg nano-zirconia + 20 mg C for BF-500-3. The optimized purification procedures provided satisfactory recoveries for all tested fungicides with rates between 91% and 107% and relative standard deviations between 3.7% and 9.6%. The limits of detection and quantification were in the range of 0.0360-0.272 μg/kg and 0.120-0.910 μg/kg. Based on this method, the dissipation of pyraclostrobin, picoxystrobin and its metabolite in pepper fruit were determined under field conditions. Pyraclostrobin and picoxystrobin degraded rapidly with half-lives of 5.53-7.02 and 5.97-7.82 days and 5.09 and 5.68 days in 2016 and 2017, respectively. The residue levels of BF-500-3 increased first and then decreased. The terminal residues of all fungicides were below the maximum residue limits (MRLs). This research can not only provide guidance for the reasonable usage of pyraclostrobin and picoxystrobin in agriculture but also give a reference for the Chinese government to establish the MRL for pyraclostrobin in pepper.
本研究采用改良的 QuEChERS 前处理与超高效液相色谱-串联质谱联用技术，建立了一种同时分析辣椒果实中吡唑醚菌酯、唑菌酯及其代谢物 BF-500-3 残留的高效、灵敏的分析方法。利用化学计量学工具优化了 QuEChERS 净化步骤。逐步回归和曲面响应模型表明，吡唑醚菌酯和唑菌酯的最佳吸附剂混合物为 40mg 纳米氧化锆+10mg C，BF-500-3 的最佳吸附剂混合物为 30mg 纳米氧化锆+20mg C。优化的净化程序为所有测试杀菌剂提供了令人满意的回收率，回收率在 91%至 107%之间，相对标准偏差在 3.7%至 9.6%之间。检测限和定量限在 0.0360-0.272μg/kg 和 0.120-0.910μg/kg 范围内。基于该方法，在田间条件下测定了吡唑醚菌酯、唑菌酯及其代谢物在辣椒果实中的消解动态。吡唑醚菌酯和唑菌酯在 2016 年和 2017 年的半衰期分别为 5.53-7.02 天和 5.97-7.82 天，5.09 天和 5.68 天，降解迅速。BF-500-3 的残留水平先增加后减少。所有杀菌剂的最终残留量均低于最大残留限量（MRLs）。本研究不仅为农业上合理使用吡唑醚菌酯和唑菌酯提供了指导，也为中国政府制定辣椒中吡唑醚菌酯的 MRL 提供了参考。
