determination of some polycyclic aromatic hydrocarbons in the caspian seawater by hplc following preconcentration with solid-phase extraction

a solid-phase extraction (spe) method for sample clean-up and preconcentration followed by reversed-phase high-performance liquid chromatography (rp-hplc) with uv detection is reported for determination of polycyclic aromatic hydrocarbons (pahs) in the caspian seawater. a good resolution was obtained using acetonitrile:water (40:60) as mobile-phase for separation of these compounds. the effect of experimental variables, such as breakthrough volume with different concentrations of pahs, type and volume of solvents for elution step were studied in spe using c18 cartridge as sorbent. different solvents (methanol, hexane and chloroform) were used for elution step in spe. the best solvent for elution was hexane with volume of 3 ml, recoveries  over 82 % and relative standard deviations lower than 6 %. detection limits ranging from 0.02 to 0.14µgml -1 were obtained for different pahs using hplc method. concentration of pahs in the caspian seawater were 0.34 to 14.11 ngml -1.