凝胶渗透色谱法测定食用植物油中苯并(a)芘

Determination of Benzo(a) Pyrene in Edible Vegetable Oils by Gel Permeation Chromatography

建立简便、准确的食用植物油中苯并(a)芘测定的凝胶渗透色谱-液相色谱荧光检测方法。样品经环己烷-乙酸乙酯(1∶1,V/V)溶解,利用凝胶渗透色谱系统净化,洗脱液经真空旋转蒸发浓缩后氮吹至干,乙腈定容后用带荧光检测器的高效液相色谱仪测定。结果,苯并(a)芘在0.21~52.50 ng/m L范围具有良好的线性,检出限为0.2 μg/kg,最低定量限为0.7 μg/kg,灵敏度高、线性好、范围宽。三级大豆油、四级菜籽油、一级菜籽油、一级山茶油、芝麻油、橄榄油共6种不同种类和级别的食用植物油加标样品中低、中、高3个添加水平的回收率在98.6%~103.5%之间,相对标准偏差(n=6)在2.98%~4.69%之间。2 a跟踪测定1份芝麻油阳性样品10次,其平均值为10.94 μg/kg,相对标准偏差为2.12%。建立的方法操作简单,能有效去除油脂基质的干扰,准确度高,重复性好,克服了GB/T 22509—2008《动植物油脂苯并(a)芘的测定:反相高效液相色谱法》方法测定苯并(a)芘时氧化铝活度不易控制的技术难题,检测批量植物油样品中苯并(a)芘时效率提高。

A gel permeation chromatography(GPC) method for sample clean-up, followed by high performance liquid chromatography(HPLC) with fluorescence detection was developed for the determination of benzo(a)pyrene(Ba P) in edible vegetable oils. The samples were cleaned up by GPC, evaporated under vacuum atmosphere and then determined by HPLC. The results showed this method was sensitive and had a good linearity within the concentration range of 0.21–52.50 ng/m L. The limit of detection was 0.2 μg/kg and the limit of quantization was 0.7 μg/kg. The mean recoveries of standard additions in different kinds and grades of edible vegetable oils were between 98.6% and 103.5%, with relative standard deviations(RSDs)(n = 6) in the range of 2.98%–4.69%. The average of ten repeated determinations of Ba P in one positive sample during the years 2011 to 2013 was 10.94 μg/kg with a RSD of 2.12%, suggesting good repeatability of this method. This GPC-HPLC method is simple, sensitive and reliable for the determination of benzo(a)pyrene in edible vegetable oils.