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为了考察食用油中7种指示性多氯联苯（PCBs）的残留情况，建立了食用油中痕量多氯联苯测定的双重净化-气相色谱法。以乙腈提取样品，提取液浓缩至干后用正己烷溶解，经浓硫酸、硅胶分散固相萃取双重净化后进行气相色谱分析，外标法定量。优化的色谱条件为：HP-5石英毛细管柱（30 m×0.32 mm×0.25μm）程序升温分离，流速0.8 mL / min，进样量1.00μL，电子捕获检测器检测。结果表明：在优化的条件下，7种多氯联苯在10~500μg / L范围内线性良好，相关系数大于0.999，不同基质中的检出限（ S / N =3）范围为1.8~8.9μg / kg，定量限（ S / N =10）范围为5.9~29.8μg / kg。在橄榄油、花生油和棕榈油空白样品中添加10、20、100μg / kg 3个水平的7种多氯联苯，其加标回收率范围为71.0％~105.5％，相对标准偏差（ RSD）范围为4.0％~11.3％。该方法具有操作简便、快速、准确的特点，可用于植物油中指示性多氯联苯残留量的日常检测。

To investigate the residues of seven indicator polychlorinated biphenyls( PCBs)in vegetable oils,a method was established for the determination of trace PCBs in vegetable oils by double clean-up coupled with gas chromatography( GC). After extracted with acetonitrile, the sample extract was concentrated to dryness followed by re-dissolving with hexane. And the solution was pretreated by adding concentrated sulfuric acid followed cleaned-up with silica gel in dispersive solid-phase extraction protocol,then analyzed by GC with external standard meth-od. Under the optimized chromatographic conditions,the analysis was carried out with a capil-lary column(HP-5,30 m×0. 32 mm×0. 25 μm)at a flow rate of 0. 8 mL / min,and the sample volume was 1. 00 μL. Monitoring with an electron-capture detector,all the target analytes were separated by temperature-programming of the column. Good linearities were obtained in the range of 10-500 μg / L for the seven indicator PCBs with the correlation coefficients greater than 0. 999. For different matrices,the limits of detection(S / N = 3)and limits of quantitation(S / N= 10)were in the range of 1. 8-8. 9 μg / kg and 5. 9-29. 8 μg / kg,respectively. At three spiked levels of 10,20 and 100 μg / kg of the seven indicator PCBs in olive oil,palm oil and peanut oil blank samples,the average recoveries ranged from 71. 0% to 105. 5% with the RSDs of 4. 0% -11. 3% . The method is simple,rapid and accurate,and can be used for the routine analysis of the indicator PCBs in vegetable oils.