Simultaneous determination of polycyclic aromatic hydrocarbons and their chlorinated derivatives in grilled foods

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are unintentionally generated in foods that are cooked, and dietary ingestion of these PAHs is regarded as the dominant route of exposure to PAHs. Some chlorinated PAHs (ClPAHs) are more toxic than their corresponding parent PAHs and can also be generated in food during cooking. Knowledge of the concentrations of ClPAHs in cooked foods has been limited by the lack of an adequate analytical method for measuring ClPAH concentrations in cooked foods. In this study, we developed an analytical method for simultaneous determination of PAHs and ClPAHs in lipid-rich foods. The combination of a potassium hydroxide silica gel column and an activated carbon cartridge enabled us to simultaneously measure PAH and ClPAH concentrations in raw and grilled fish and meats. Twelve kinds of PAHs (e.g., fluorene [Fle], phenanthrene [Phe], fluoranthene [Flu], and pyrene [Pyr]) were detected in grilled foods. The concentrations ranged from below the limit of quantitation (<LOQ) to 310 ng g^-1. We also detected 9-monochlorinated Phe (9-ClPhe), 3-monochlorinated Flu (3-ClFlu), 8-monochlorinated Flu (8-ClFlu), and 1-monochlorinated Pyr (1-ClPyr); those concentrations ranged from <LOQ to 0.16 ng g^-1. The total concentrations of PAHs were significantly lower in gas-grilled meats than in charcoal-grilled meats. In contrast, the concentrations of ClPAHs were significantly higher in gas-grilled meats than in the charcoal-grilled meats. This pattern could be attributed to the difference of reaction temperatures needed to generate them. Toxic equivalent (TEQ) concentrations, which were calculated based on toxicities relative to benzo[a]pyrene (BaP), were much higher in the grilled foods (0.12-12 ng-BaP_eq g^-1) for PAHs than for ClPAHs (<LOQ to 0.026 ng-BaP_eq g^-1).

Keywords: Analytical method; Chlorinated polycyclic aromatic hydrocarbons; Food; Polycyclic aromatic hydrocarbons; Unintentional generation.