Unequivocal identification and quantification of PAHs content in ternary synthetic mixtures and in smoked tuna by means of excitation-emission fluorescence spectroscopy coupled with PARAFAC

It is well known that several polycyclic aromatic hydrocarbons (PAHs), products of incomplete pyrolysis of organic material, have proved to be extremely toxic to humans. Food can be contaminated by these compounds in many different ways and diet represents nowadays the major source of exposure to PAHs for non-smokers population. In the present study, three of the most important carcinogenic PAHs in foods, according to the legislation currently in force, i.e. benzo[alpha]pyrene (BaP), benzo [alpha] anthracene (BaA) and chrysene (Chry), were firstly arranged in ternary mixtures, following an experimental design. Then, an organic extraction from a commercial smoked tuna, potentially affected by PAHs, was performed to investigate the presence of the three compounds under study. A spectrofluorimetric method based on the second order calibration of excitation-emission fluorescence matrices (EEMs) and parallel factor analysis (PARAFAC) decomposition was proposed in this work as analytical approach for PAHs detection. Both in the ternary mixtures and in the food matrix (smoked tuna), PAHs were unequivocally identified and quantified with decision limit (CC alpha) and capability of detection (CC beta) equal to 0.11 mu g L-1 and 0.21 mu g L-1 for BaP, 0.27 mu g L-1 and 0.53 mu g L-1 for BaA and 0.18 mu g L-1 and 0.35 mu g L-1 for Chry, respectively, when the probabilities of false positive (alpha) and false negative (beta) were fixed at 0.05. In the investigated smoked tuna, detectable levels of BaP were found, whereas BaA and Chry were absent.