EN
The effect of different solvents on extraction with liquid carbon dioxide was studied. Extracted polynuclear aromatic hydrocarbons (PAHs) were applied on Sephadex C-50 gel. The model PAHs were phenanthrene, pyrene and benzo(a)pyrene. It is stated that the percentage of PAH model extractions was diminished when water-immiscible solvents (cyclohexane, chloroform and benzene) and methanol were added to the system. The addition of acetone and dimethylformamide caused increases in extraction percentage. The optimum content of both these solvents was shown to be approximately 0.8% in relation to the volume of C02 used .Under these conditions, a single extraction in the presence of acetone made it possible to recover 67% of phenanthrene, 62% of pyrene and 86% of benzo(a)pyrene, whereas in the presence of dimethylformamide these numbers were 66%, 80% and 9%, respectively.