磁纳米材料净化-超高效液相色谱-串联质谱测定猕猴桃中多农药残留

建立了基于磁性纳米材料的样品中多农药残留的快速前处理方法，并与超高效液相色谱-串联质谱（UPLC-MS/MS）联用，构建了猕猴桃中52种农药及8种相关代谢物的定量分析方法。选择可有效去除猕猴桃基质中主要干扰源的磁性纳米材料--N-丙基乙二胺修饰的四氧化三铁（Fe₃O₄-PSA）和商品化C18吸附剂共同作为净化吸附剂，深入探讨了净化吸附剂用量对农药回收率的影响。结果表明，目标化合物在2~250 μ g/L范围内线性关系良好，在3个添加水平下的平均回收率为76.0%~121%，相对标准偏差不大于13.8%。与以非磁性材料为净化剂的QuEChERS方法相比，该方法处理等量样品时可节约样品前处理时间，展现出良好的应用前景。

Determination of pesticide multiresidue in kiwifruit by magnetic nanoparticles adsorbent purification and ultra performance liquid chromatography- tandem mass spectrometry

A simple and fast sample purification method was developed based on magnetic nanoparticles. The present work aimed at purifying the analytes by removing the matrix interferences. Magnetite Fe₃O₄ nanoparticles modified with N-(n-propyl)ethylenediamine (Fe₃O₄-PSA) and the commercial C18 were selected as the cleanup adsorbents. They can remove the target interferences of the matrixes, such as organic acids and non-polar compounds. The amounts of Fe₃O₄-PSA and C18 were systematically optimized for selecting the suitable purification conditions. The simultaneous determination of 52 pesticides and 8 related metabolites in kiwifruit was established by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Method validation was performed including the linearity, sensitivity and matrix effect of the method. The results displayed that these pesticides showed good linearities ranging from 2 to 250 μ g/L. The recoveries of the kiwifruit samples at three spiked levels ranged from 76.0% to 121% with the relative standard deviations (RSDs) less than 13.8%. Compared with the QuEChERS method based on PSA and C18, the present method can save the pretreatment time, giving the high throughput analysis possible. It can also satisfy the requirement of the pesticide residue analysis, displaying good application prospect and provide a novel method for rapid determination of pesticide multiresidue in kiwifruit.