Efficiency of the microwave-assisted extraction of hydrocarbons and pesticides from sediments

A mixture of toluene and water is proposed for the microwave-assisted extraction of organic pollutants, hydrocarbons and pesticides, from marine sediments. The effect of experimental conditions, such as microwave power and irradiation time, on the extraction of linear, unresolved and polycyclic aromatic hydrocarbons as well as PCBs and DDTs has been evaluated using real marine sediment samples. Values found by Soxhlet and ultrasonic extraction were employed to evaluate the efficiency of the microwave-assisted extraction. Analytical determinations were carried out by gas chromatography using FID, ECD and MS detectors. For 2 g of a dry sediment, an extraction time of 6 min with 10 ml toluene and 1 ml water provides a complete extraction of 15 linear hydrocarbons, 19 polycyclic aromatic hydrocarbons, 4 DDTs and 6 PCBs congeners. Recovery percentage values varies from 107% to 98.5% as compared with the Soxhlet extraction.