Assessing polycyclic aromatic hydrocarbons in cereal-based foodstuffs by using a continuous solid-phase extraction system and gas chromatography-mass spectrometry

Polycyclic aromatic hydrocarbons (PAHs) are a family of sixteen compounds of which are deemed priority pollutants by the European Commission and the US Environmental Protection Agency for their carcinogenic and mutagenic properties. A method for their determination in a variety of cereal-based foodstuffs including bread, cookies, flours and cereals is reported here. The method uses solid-liquid extraction with a semi-automated solid-phase extraction system to clean up sample extracts, and gas chromatography-mass spectrometry to determine and quantify the target analytes. The analytical figures of merit of the proposed method, which include high precision, sensitivity and selectivity for all 16 PAHs, testify to its robustness. Thus, the limits of detection for 1 g of sample span the range from 2 to 60 ng kg−1, relative standard deviations are all lower than 7.5% and recoveries range from 88 to 103%. The method was successfully applied to several cereal-based foodstuffs samples. The European Commission has set a tolerated limit of 1 μg kg−1 for PAH4 [a combination of benzo(a)pyrene, benzo(a)anthracene, benzo(b)fluoranthene and chrysene] in cereal products for infants that was exceeded by three breakfast cereal foodstuffs (3.1-7.5 μg kg−1). Also, home toasting bread was found to raise the concentrations of some PAHs above the allowable levels.