超高效液相色谱-四极杆-飞行时间质谱法快速筛查辣椒粉中27种农药残留

建立了超高效液相色谱-四极杆-飞行时间质谱（UPLC-Q-TOF/MS）快速筛查辣椒粉中27种农药残留的检测方法。样品采用乙腈提取，经Carb/NH₂固相萃取小柱净化，用乙腈-乙酸乙酯（3：1，v/v）洗脱，电喷雾正离子模式检测。在一级质谱模式下，以目标物的保留时间、精确质量数、同位素分布和同位素丰度比定性，以准分子离子峰的峰面积定量。在Targeted MS/MS模式下，通过相应碰撞能量下的离子碎片信息进一步确证。27种化合物在各自的线性范围内线性关系良好，相关系数均大于0.997。27种化合物的定量限为2.5~5.0 μg/kg，在3个添加水平下的回收率为72.3%~118.9%，相对标准偏差（RSD）为0.21%~12.7%（n=6）。该方法快速、灵敏、准确，适用于辣椒粉中多种农药残留的同时检测。

Rapid screening of 27 pesticide residues in chili powder by ultra performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry

An analytical method was established for the simultaneous determination of 27 pesticide residues in chili powder by ultra performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UPLC-Q-TOF/MS). The samples were extracted with acetonitrile, and cleaned-up by solid phase extraction (SPE) with Carb/NH₂ cartridges, and eluted with acetonitrile-ethyl acetate (3: 1, v/v). The eluent was determined by UPLC-Q-TOF/MS with electrospray ionization in positive mode. The confirmatory analysis was carried out by comparing the retention times, accurate masses, isotope abundance and isotope spacing of all the compounds and fragment ions with Targeted MS/MS. The correlation coefficients (r) were greater than 0.997 in the linear ranges of the 27 pesticides. The limits of quantification (LOQs) of the 27 pesticides were 2.5-5.0 μg/kg. At the three spiked levels, the recoveries were between 72.3% and 118.9%, with the relative standard deviations (RSDs, n=6) ranging from 0.21% to 12.7%. The method is efficient, sensitive and accurate, and can meet the requirement of the determination of the 27 pesticides in chili powder.