| 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. |
