Simultaneous determination of halogenated contaminants and polycyclic aromatic hydrocarbons: a multi-analyte method applied to filter-feeding edible organisms

This study develops and validates a novel analytical approach for the simultaneous determination of 127 polychlorinated biphenyls (PCBs), together with 6 polychlorinated naphthalenes (PCNs) and 16 polycyclic aromatic hydrocarbons (PAHs). PCBs, PCNs, and PAHs were subjected to a unique pretreatment protocol and were simultaneously determined in a single chromatographic run, using GC-MS, in environmental marine samples of mussels and clams. The results of the validation experiments, which were performed on the standard reference materials (NIST SRM 1974C - slurried matrix and NIST SRM 2977 - freeze-dried matrix), were in accordance with the certified and the reference values. The repeatability of the method for all target compounds, expressed as mean relative standard deviations, ranged from 2.5 to 5.1 % for PCBs, from 3.9 to 5.5 % for PCNs, and from 8.6 to 17.9 % for PAHs; the first value of each pair refers to the freeze-dried matrix and the second to the fresh one, for each of the classes of compounds examined. The quantification limits were in the range of 0.2-6 pg for PCBs, 0.4-8 pg for PCNs, and 0.2-15 pg for PAHs (on column). The method recoveries yielded good results (62 +/- 19 % for the freeze-dried matrix and 60 +/- 14 % for the fresh one) and were not significantly reduced by adopting a single analytical protocol compared with the use of different group-specific analytical methods. No serious interferences were encountered and good selectivity was achieved. These results show that this method allows one to increase the laboratory sample throughput while requiring a small amount of tissue and saving time.