Rapid determination of polycyclic aromatic hydrocarbons in natural tocopherols by high-performance liquid chromatography with fluorescence detection

A simple and rapid method has been developed and validated for the determination of seventeen polycyclic aromatic hydrocarbons (PAHs) in natural tocopherol products. Samples were dissolved in n-hexane, cleaned by an alumina column, and separated and determined by reversed-phase high-performance liquid chromatography (HPLC) with fluorescence detection. The recoveries were greater than 77.9%, except for the lowest molecular weight PAHs (Na, 1-Me, 2-Me, AC, F) which were between 15.9% and 75.8%. The limits of quantification were less than 0.38 ng/g for the heavy PAHs and less than 1.50 ng/g for the light PAHs. Good repeatabilities were achieved with RSD less than 10.7% for all the objective compounds. This method has been applied to evaluating PAHs contents in various natural tocopherol products and controlling natural tocopherol product quality.