Direct extraction and separation of some polynuclear aromatic hydrocarbons (PAHs) from complex mixtures (sewage sludges) by countercurrent chromatography

The present work is the first attempt to use countercurrent chromatography for xenobiotics extraction and separation from complex natural matrices without sample pretreatment. A procedure has been developed for the direct extraction and separation of some PAHs from a sewage sludge medium being in fact a concentrated suspension. The sewage sludge and aqueous solutions containing the trace amounts (0.01-10 mu g/mL) of PAHs were used as the stationary phase in the column whereas organic solvents (n-heptane, dichloromethane) or their mixture were used as mobile phase. Taking pyrene as an example it has been shown that the recovery of PAHs can be quantitative. When no PAHs was added to the sewage sludge, pyrene was found in the sample investigated at the Level of 0.24 mu g/ml. The possibility of the subsequent separation of naphthalene, pyrene, and benzo(g,h,i)perylene from the sewage sludge medium also has been demonstrated.