Determination of selected polycyclic aromatic hydrocarbons in toasted bread by supercritical fluid extraction and HPLC with fluorimetric detection

A new method for PAHs determination in toasted bread samples is proposed. The method is based on supercritical-fluid extraction, using CO2 and acetonitrile as modifier. The extracted PAHs were collected in 1 mt acetonitrile. Quantitation was carried out by HPLC with fluorimetric detection. A Hypersil Green PAH column, acetonitrile-water gradient mobile phase, and a program of 11 excitation and emission wavelength pairs for fluorimetric detection were used. Recoveries at concentration levels in the range 0.15-3.56 mu g/kg bread were close to 100% for all PAHs except fluoranthene, chrysene, and benzo[ghi]perylene. Some PAHs were detected in these samples within the range 0.323-9.40 mu g/kg toasted bread; the relative standard deviations were in the range 2 - 12% (n=4).