SPE净化-同位素稀释-GC-MS法检测食用油脂中16种多环芳烃

摘要

A methord for the analysis of EPA16 polycyclic aromatic hydrocarbons in edible oil samples by isotope dilution gas chromatography–mass spectrometry(GC–MS)was built. In this method,the samples were pretreated by ultrasonic extraction with acetonitrile and purified by silica SPE,and then analyzed on a DB–5MS column. It reduced the consumption of organic solvent by the pretreated and purified process. The result was more accurate by the quantification of 16 isotopes. The calibration curves had good linearity within 1~100μg/kg for each pesticide(0.999>R>0.998). The limits of the detection ranged from 0.06μg/kg to 0.17μg/kg and the limits of quantitation ranged from 0.18μg/kg to 0.56μg/kg. The recoveries of 16 PAHs varied from 84.36%to 114.35%with the relative standard deviation of 0.12%~10.36%(n=6)at the spiked levels 2,5,10μg/kg. The concentrations of 16 PAHs ranged from 30.83±0.66 μg/kg to 793.13±16.96 μg/kg in the 21 tested samples. The amount of BaP and PAH4 were lower than the maximum limit of EU(BaP≤2 μg/kg,PAH4≤10μg/kg)except 5 roasted oil samples and 1 peanut oil. The pollution of the PAHs in the roasted oil was more serious. The risk of the PAHs in the roasted oil was more serious than the extracted refined oil and the cold pressing oil.%研究建立了乙腈超声提取、硅胶SPE柱净化、DB–5MS毛细管柱分离、同位素稀释法定量检测食用油中16种多环芳烃的气质联用（GC–MS）方法。油脂样品采用乙腈提取、硅胶SPE柱净化，减少了有机溶剂的消耗，再采用16种同位素内标法定量，定量结果更加准确。结果表明：16种多环芳烃在1~100μg/kg范围内线性关系良好，线性相关系数为0.9989~0.9999，检出限为0.06~0.17μg/kg，定量限为0.18~0.56μg/kg。16种目标物在2、5、10μg/kg加标水平下的各组分回收率在84.36%~114.35%之间，相对标准偏差在0.12%~10.36%之间（n=6）。21个受测样品中16种多环芳烃的总含量为30.83±0.66~793.13±16.96μg/kg。除全部浓香型油脂及1个花生油外，所有受试油样中BaP和PAH4含量均达到欧盟限量指标（BaP≤2μg/kg，PAH4≤10μg/kg），浓香型油脂样中PAHs的污染情况较为严重。从油脂品类来看，低温制油和浸出精炼成品油的多环芳烃的风险低于浓香型油脂。