Use of Supercritical Fluid Extraction-High Performance Liquid Chromatography in the Determination of Polynuclear Aromatic Hydrocarbons from Smoked and Broiled Fish

Polynuclear aromatic hydrocarbons (PAHs) from smoked and broiled fish were isolated by supercritical fluid extraction (SFE), and quantitatively determined by reversed phase liquid chromatographic (RP-HPLC) methods. The SFE-method was tested first with inert matrix. As expected, the extraction of PAHs from quartz sand gave good recoveries ranging from 80 to 100 % with R.S.D. of 3–11 %. The extraction of fish material showed that methanol had to be used as a modifier, because larger PAH molecules were weakly extracted with pure CO2. The use of methanol resulted in, however, that lipophilic compounds were co-eluting in greater amounts, interfering the analysis of PAHs by HPLC - UV. That is why the extracts were purified using solid phase extraction (SPE) prior to chromatographic determination. The extraction of one sample was completed in 20 minutes, while several hours are consumed in the conventional solvent extraction methods. The sensitivity of the method used is in ppb-range, which corresponds well with the concentration of PAHs in smoked fish products.