食用植物油中矿物油污染物的分析进展

矿物油是C_(10)~C_(50)烃类化合物的总称,包括直链、支链和环状烷烃以及烷基取代芳烃两大类,化学成分复杂。食用植物油中普遍存在矿物油污染,含量达到1~1 000 mg/kg,矿物油污染来源广泛,涉及原料的采收、运输、加工和油脂的精炼、包装与储存等过程。植物油中干扰矿物油分析的成分较多,如甘油三酯、奇数碳正构烷烃、角鲨烯、甾烯、胡萝卜素等,需要采用适当方法排除。由于矿物油组成复杂,目前常用具有等碳响应的氢火焰离子化检测器分析含量,其中液相色谱-气相色谱联用是测定矿物油的理想技术。考虑到普及性问题,一些实验室开发了固相萃取结合大体积进样气相色谱法。综述了国内外近十年来食用植物油中矿物油的分析方法,以期为我国油脂及其相关产品中矿物油的检测工作提供参考。

Progress in analysis of mineral oil contaminants in edible vegetable oils

Mineral oils are general name of a large number of hydrocarbons ranging from C10 to C50, including highly complex mixtures, principally straight, branched alkanes and alkyl-substituted cyclo-alkanes and aromatic hydrocarbon. Mineral oil contaminants were present in almost all edible vegetable oils with content at 1-1 000 mg/kg. The contaminants come from a variety of sources,including harvesting, transporting, processing of material and refining, packaging and storage of oil. Usually, vegetable oil samples contain triglycerides, endogenous odd-number n-alkanes, squalenes, sterenes and carotenes, all of which are miscible with the mineral oils. Thus, it is a challenging task to determine mineral oil contaminants in vegetable oils due to removing those interferences in sample matrix. In addition, because of the complexity of mineral oil composition, the common mean to measure their total amount is hydrogen flame ionization detector, in which the ideal analysis instrumentation for determining mineral oils is on-line liquid chromatography-gas chromatography. Considering the pervasive problem, off-line solid phase extraction combined with large volume injection-gas chromatography is developed. The analysis methods of mineral oils in edible vegetable oil at home and abroad in recent ten years were systematically reviewed to provide references for domestic oil manufactures to determine mineral oil in oil products and oil-base food.