Determination of polycyclic aromatic hydrocarbons in smoked fish samples by a new microextraction technique and method optimisation using response surface methodology.

Microwave-assisted extraction coupled with dispersive liquid-liquid microextraction as a recently introduced method was applied to determine polycyclic aromatic hydrocarbons in Iranian smoked fish. The results showed that the interaction of hydrolysing solution volume with ethanol ratio, volumes of extracting and disperser solvent is significant in the obtained model. Optimized conditions were: a hydrolysing solution volume 10 ml with 50% ethanol, a pH of 5, and extracting and disperser solvent volumes of 150 and 500 μl respectively. The level of 16 polycyclic aromatic hydrocarbons (PAHs) was determined in 80 smoked fish consisting of four species. The contamination of benzo[a]pyrene in all samples except three was below the European Commission's maximum level of 2 μg kg(-1) for smoked fish, while the ∑4 PAHs (benzo[a]pyrene, chrysene, benzo[a]anthracene and benzo[b]fluoranthene) were between 3 and 12 μg kg(-1) wet weight in all samples. Of the species examined, Hypophthalmichthys molitrix had the highest PAHs (∑16).