A rapid method for polycyclic aromatic hydrocarbon determination in vegetable oils

Despite the carcinogenic properties of some PAHs, and although edible oils are particularly prone to PAH contamination, no international legal limits for PAH in edible oils have been yet established. However, a number of methods for such analyses have been published, most of which are time consuming and unsuitable for routine analysis, as they do not permit analysis of a large number of samples per day. Since sample preparation is the most time-consuming part of analysis, research to find fast sample preparation methods is of topical interest. In this paper, solid phase extraction with silica cartridges is applied as sole sample preparation step. A 250-mg sample of oil in n-hexane is loaded onto a 5 g silica cartridge and the PAH fraction is eluted with 8 mL of n-hexane/dichloromethane 70/30. After solvent evaporation, the volume was adjusted to 100 muL and injected into a HPLC equipped with a Cl 8 reverse phase column and a spectrofIuorometric detector. Results show a relatively low recovery for the more volatile PAHs (Na and Ac) and good recovery for heavy PAHs. Repeatability is quite satisfactory, as coefficients of variation range between 5.0 and 13.0%.