Enrichment of benzo[a]pyrene in smoked food products and determination by high-performance liquid chromatography-fluorescence detection

We developed a procedure for trace enrichment of benzoa]pyrene (BP) in extracts of smoked food products, and an HPLC-fluorescence detection (FL) method for determination of BP in the enriched extracts. The procedure consists in extraction/sonication of the lyophilized product in hexane, clean-up of the hexane extract by passage through a Sep-Pak Silica Plus cartridge and, subsequently, by partitioning between hexane and dimethyl sulphoxide, and concentration of the BP using a Sep-Pak C18 Plus cartridge. HPLC-FL and quantification limits were 0.049 microgram/l in acetonitrile (< 0.0067 microgram/kg of smoked food) and 0.089 microgram/l in acetonitrile (< 0.012 microgram/kg), respectively. Recovery (94.1%) and RSD (< 8.65%) were satisfactory. When applied to 15 types of sausage, mean BP content was 0.022 microgram/kg, and all but two samples (both treated with wood smoke) had BP contents below the 0.03 microgram/kg limit imposed in EU legislation for smoking-flavour agents.