Concentration, separation and determination of hydrocarbons in sea water

A method for determining the hydrocarbons dissolved in sea water, including their concentration and separation into homogeneous classes, is described. Extraction with organic solvents, determination of the optimum volumes for n-hexane and carbon tetrachloride and concentration procedures for the extracts were investigated. Separation of hydrocarbons from polar compounds and their fractionation into five classes (aliphatic, monoaromatic and polynuclear with 2, 3–4 and 5–6 rings) were achieved using adsorption chromatography on a two-step microcolumn of silica gel and aluminium oxide. The overall recovery efficiency of the procedures and the detection limits of several hydrocarbons in 11 of sea water are reported.