Efficient extraction of PAHs in aqueous organised media assisted by focused microwaves

A novel method for the extraction into an aqueous medium of PAHs in soil is described, where sodium dodecyl sulphate (SDS) is used as micelle former. After optimisation of this step using a multivariate approach, recoveries o f the target analytes from spiked soil ranging between 98.3%-99.7% were obt ained when the samples were subjected to extraction with 25 mL of an aqueou s SDS solution (2.9 10(-2) mol L-1) while irradiated with focused microwave s at 240 W for 40 min. The overall method involving determination of the ex tracted compounds consists of three steps: 1) extraction of the analytes in to the aqueous micellar medium assisted by focused microwaves; 2) trapping of the analytes on a C-18 cartridge for clean up and preconcentration and; 3) HPLC separation with fluorimetric detection. The method was validated us ing the certified reference material CRM 524 and the results found were in agreement with the certified values.