Liquid chromatographic determination of trace residues of polynuclear aromatic hydrocarbons in smoked foods.

A liquid chromatographic (LC) method was developed and applied to the determination of polynuclear aromatic hydrocarbons (PAHs) in a variety of smoked, market basket commodities. The PAHs are extracted with 1,1,2-trichloro-1,2,2-trifluoroethane (Freon 113) from alcoholic KOH digests of the commodities. The extracts are purified by column chromatography through a deactivated silica gel/alumina column and by liquid-liquid partitioning between dimethyl sulfoxide and cyclohexane before separation of the PAHs by LC. Both fluorescence and UV detectors are used to monitor the LC column effluent to detect nanogram quantities of PAHs. Trace levels of carcinogenic and non-carcinogenic PAHs were found in all samples analyzed, although generally at less than 1 ppb levels.