Organophosphorus Pesticide in Sapodilla (Manilkara zapota) Fruit

A method based on QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction and gas chromatography-mass spectrometry (GC-MS) detection was described for the pesticides dichlorvos, disulfoton, ethoprophos, parathion methyl, fenchlorphos, chlorpyrifos, azinphos methyl and prothiofos in sapodilla. For all compounds studies, it was observed a strong matrix effect showing the need to use matrix matched calibration strategy. Method was validated, and good linearity (R > 0.99) was obtained for all pesticides studied with limits of detection (LODs) and quantification (LOQs) ranging from 0.01 to 0.06 mg kg-1 and 0.03 to 0.2 mg kg-1, respectively. Recovery studies were performed at different levels (0.08, 0.10, 0.14, 0.20, 0.35 and 1.17 mg kg-1) and showed good results (between 70 and 120% with relative standard deviation (RSD) < 20%). A statistical test was applied to the coefficients of the analytical curves obtained in the sapodilla matrix. Analyses of commercial samples showed chlorpyrifos were detected in about 70 and 33% for fruit and pulps samples, respectively. It should be noted that chlorpyrifos is not permitted in sapodilla crops by ANVISA and EC guidelines.

本研究建立了一种基于QuEChERS（快速、简便、廉价、高效、耐用、安全）前处理结合气相色谱-质谱联用法（GC-MS）的检测方法，用于测定人心果（sapodilla）中8种农药残留，包括敌敌畏、乙拌磷、灭线磷、甲基对硫磷、皮蝇磷、毒死蜱、甲基谷硫磷与丙硫磷。针对所有被测化合物，均观察到显著的基质效应，提示需采用基质匹配校准策略。本方法经方法学验证，所有目标农药均表现出良好的线性关系（R>0.99），检出限（LODs）与定量限（LOQs）分别为0.01~0.06 mg·kg⁻¹和0.03~0.2 mg·kg⁻¹。加标回收实验在0.08、0.10、0.14、0.20、0.35及1.17 mg·kg⁻¹共6个浓度水平下开展，结果显示回收率处于70%~120%区间，相对标准偏差（RSD）<20%，方法性能良好。对人心果基质中得到的分析曲线系数进行了统计学检验。市售样品分析结果表明，果实样品与果肉样品中毒死蜱的检出率分别约为70%和33%。需特别说明的是，根据巴西国家卫生监督局（ANVISA）与欧盟委员会（EC）的相关法规，人心果种植中禁止使用毒死蜱。