Estimation of nitropolycyclic aromatic hydrocarbons in foods

A method is described for the sample clean-up and estimation of nitropolycyclic aromatic hydrocarbons (nitro-PAH) in foods. The analysis involves the novel use of a coupled capillary gas chromatograph/thermal energy analyser and provides a detection limit for 1-nitropyrene of 12 pg (equivalent to 0.02 micrograms/kg for a 50-g sample). Only 3 out of 24 samples contained detectable quantities of nitro-PAHs; these were in the range 0.2-2.0 micrograms/kg. In contrast to the widespread occurrence of the parent PAHs in foodstuffs, the presence of nitro-derivatives appears to be minimal.