气相色谱-三重四极杆串联质谱法测定4种果品中99种农药残留

建立了红枣 (干)、杏、葡萄和香梨4种果品中99种农药残留量的气相色谱-串联质谱(GC-MS/MS)分析方法。样品用乙腈提取，氯化钠盐析并离心，上清液经分散固相萃取净化，丙酮溶解定容后，GC-MS/MS测定。对比了Carb/NH₂固相萃取柱和NH₂ + C₁₈ + GCB、N-丙基乙二胺 (PSA) + C₁₈ + GCB 3种净化方法的净化效果。结果表明:应用优化的前处理方法，采用基质匹配校准曲线，在0.005~0.5 mg/L范围内，4种基质线性关系良好 (R2 ≥ 0.9915)，定量限(LOQ)范围为0.01~0.025 mg/kg；在0.01、0.025、0.05和0.1 mg/kg 4个添加水平下，95种农药 (占总数96%)的平均回收率在70%~120% 之间，相对标准偏差在0.3%~20% 之间。该方法简便快捷，灵敏度、正确度、精密度均满足日常检测需求，可用于上述4种果品中农药多残留的快速测定。

Determination of 99 pesticide residues in four fruit products by gas chromatography-tandem mass spectrometry

A gas-chromatography-tandem mass spectrometry (GC-MS/MS) method was established for simultaneous determination of 99 pesticide residues in four matrices, including dried red dates, apricots, grapes and pears. Samples were extracted with acetonitrile, salted out by sodium chloride, and centrifuged. The supernatant was purified by dispersive solid phase extraction (d-SPE), concentrated and dissolved in acetone to volume, and determined by GC-MS/MS. Three cleanup approaches were compared, including solid phase extraction (SPE) with Carb/NH₂ SPE column, dispersive solid phase extraction (d-SPE) with NH₂ + C₁₈ + GCB, and d-SPE with primary-secondary amine (PSA) + C₁₈ + GCB. The results showed that d-SPE with PSA + C₁₈ + GCB were favorable than the other two approaches. Applying the optimized method, targeted compounds were quantified by the matrix-matched external standard calibration method. The calibration curves in four matrices were in the range of 0.005-0.5 mg/L with good coefficient (R2 ≥ 0.9915), and the limits of quantification (LOQs) ranged from 0.01 to 0.025 mg/kg. At four spiked levels of 0.01, 0.025, 0.05, and 0.1 mg/kg, the average recoveries of 95 pesticides (96% of total) were 70%-120% and the relative standard deviations (RSD) were 0.3%-20%. The method is simple and efficient, and the sensitivity, accuracy, and precision can meet the routine testing requirements. It is suitable for the simultaneous determination of multiple pesticide residues in the above four fruit matrices.