Polycyclic aromatic hydrocarbon profile analysis of high-protein foods, oils, and fats by gas chromatography

Abstract

A method is described for the determination of polycyclic aromatic hydrocarbons (PAHs) with 3-7 rings in (I) meat, poultry, fish, and yeast; and (II) oils and fats. The extraction of PAHs from group I is incomplete, and, therefore, group I samples must be dissolved homogeneously by saponification in 2N methanolic potassium hydroxide. The PAHs are concentrated by liquid-liquid extraction (methanol-water-cyclohexane, N,N - dimethylformamide - water-cyclohexane) and by column chromatography on Sephadex LH 20. The PAHs are separated by high-performance gas-liquid chromatography (GLC) with columns containing 5% OV-101 on Gas-Chrom Q and estimated by integration of the flame ionization detector signals in relation to an internal standard (3,6-dimethylphenanthrene and/or benzo(b)chrysene). The sensitivity is significantly higher than that obtained with ultraviolet spectroscopic methods. The reproducibility and margin of error were tested with meat samples fortified with 11 PAHs and with samples of sunflower oil. The method was further applied to meat, smoked fish, yeast, and unrefined sunflower oil. All samples investigated contained more than 100 PAHs (characterized by mass spectrometry) of which only the main components were determined: phenanthrene, anthracene, fluorene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene + benzo (j)fluoranthene + benzo(k) fluoranthene, benzo(e)pyrene, benzo(a)pyrene, perylene, dibenz(a,j)anthracene, dibenz(a,h)anthracene + indeno(1,2,3,-cd)pyrene, benzo(ghi)perylene, anthanthrene, and coronene. In contrast to other methods, the GLC profile analysis allows the recording of known and unknown PAH peaks simultaneously and also allows a compilation of all PAHs.