Rapid dioxin-like polychlorinated biphenyls (DL-PCBs) and hexachlorobenzene (HCB) determination in fish by HPLC-GC-MS negative chemical ionization mode

The correct identification and quantification of mono-ortho and coplanar congeners allows the attribution of the WHO-TEFs (Van den Berg et al., 1998) and to calculate the TEQs. A rapid analytical method for PCBs and hexachlorobenzene determination was tuned. Briefly it consisted of: a) sample previously lyophilized was submitted in a ratio 1/10 (w/v) to solvent fat extraction (hexane/acetone, 50/50 v/v); b) the fat recovered was diluted 1/5 with 13C HCB and PCBs isotopes; c) to remove fat and other source of interference, HPLC pre-separation was achieved using a silica column and a three way valve; d) the GC separation was conducted by on-column injection into ZB5MS column (Zebron, 60 m, 0.25 mm i.d., 0.25 μm film thickness) while detection operated in negative chemical ionization SIM mode using methane as reagent gas. As regard quality analysis percent recovery was nearly 100%, repeatability was