Presence of Polycyclic Aromatic Hydrocarbons in Surface Waters Used for the Production of Drinking Water

Two methods widely applied for isolating PAH from surface water have been compared: solvent extraction using cyclohexane and solid surface extraction. Higher recoveires were obtained through solvent extraction, while the reproducibility for both methods was similar. In spite of the higher costs solvent extraction was selected for further use. Results obtained on surface water samples were strongly influenced by the presence of suspended material. PAH were shown to be mainly associated with the larger suspended particles which are removed easily through sedimentation in impoudment reservoirs. The results obtained stress the need for clearly identifying the sample type (filtered or not) and the sampling point (before or after impoundment) when performing this analysis for evaluating water quality in relation to legal requirements.