气相色谱-四极杆-飞行时间质谱法快速筛查食品中182种农药残留

建立了气相色谱-四极杆-飞行时间质谱同时筛查食品中182种香港《食物内残余除害剂规例》农药残留的分析方法。样品经含0.1%（v/v）甲酸的乙腈溶液提取，改进的QuEChERS方法净化，采用Agilent HP-5MS色谱柱（30 m×0.25 mm×0.25 μm）进行分离。样品经电子轰击源电离，一级质谱采用全扫描模式完成化合物的定性和定量检测，对疑似物质进行二级谱库检索确证。考察了10种典型食品基质（大米、香菇、黄豆、菠菜、西红柿、西兰花、柚子、胡萝卜、生菜、黄瓜）的基质效应。在10~500 μg/kg范围内，182种目标化合物的线性关系良好（r>0.99），方法的定量限（S/N≥10）为10~100 μg/kg，在3个添加水平下的平均加标回收率分别为66.1%~121.5%、75.4%~125.8%、77.2%~128.9%，相对标准偏差（RSD）为0.8%~17.6%（n=6）。该方法操作简单、耗时短、灵敏度高、稳定性好，可显著降低日常筛查检测的成本，具有实际应用价值。

Rapid screening of 182 pesticide residues in foods by gas chromatography coupled with quadrupole-time of flight mass spectrometry

A method for rapid screening of 182 pesticide residues in foods according to the Hongkong regulation was developed by gas chromatography coupled with quadrupole-time of flight mass spectrometry (GC-Q-TOF/MS). The target analytes were extracted by acetonitrile with 0.1% (v/v) formic acid, then purified by a modified QuEChERS method. The separation was performed on an Agilent HP-5MS column (30 m×0.25 μm×0.25 mm). The compounds were ionized under electron impact ion source. Qualitative and quantitative detection of compounds were completed by searching accurate mass database with full scan mode. Suspected compounds can be confirmed by the spectrum database of the secondary fragment ions. The matrix effects in 10 kinds of typical foods (rice, mushrooms, soybeans, spinaches, tomatoes, broccoli, grapefruits, carrots, lettuces, cucumbers) were evaluated. The results demonstrated that the linear ranges were from 10 to 500 μg/kg with good correlation coefficients (r>0.99). The limits of quantitation were in the range of 10-100 μg/kg (S/N≥10). The average recoveries at three spiked levels were in the range of 66.1%-121.5%, 75.4%-125.8%, 77.2%-128.9% with relative standard deviations (RSDs) of 0.8%-17.6% (n=6). The method is simple, sensitive and robust, as well as having practical application for its low costs.