Determination of high molecular mass polycyclic aromatic hydrocarbons in refined olive pomace and other vegetable oils

A new and simple method has been developed for determining high molecular mass polycyclic aromatic hydrocarbons (PAHs) in refined olive pomace, and other vegetable oils from an initial sample of 0.25 g. The hydrocarbon fraction is isolated by solid-phase extraction (SPE) on silica gel using hexane as eluent. The fraction is evaporated to reduced volume and cleaned-up by SPE on an amino phase eluting with toluene. The evaporated residue, dissolved in acetonitrile, is analyzed by reverse-phase high-performance liquid chromatography with fluorescence detector using programmed excitation and emission wavelengths. The benzo(e)pyrene is determined together with other usual heavy PAHs. Interferences due to squalene and other hydrocarbons are minimized. Recoveries were greater than 80% and detection limits ranged from 0.01 to 0.2 (mu)g kg^-1. The method was validated using certified oil samples and was applied to various vegetable oils.