Abstract: The procedure of microwave-assisted extraction(MAE) of PAHs from synthetic soil samples has been studied with a MK-1 pressure automatically controlled sample-dissolving system. The digestion vessels coupled with this system were improved to suit to MAE. The optimum parameters for MAEof PAHs from soil have been studied in detail. Experimental results show that the MAEefficiency was influened by the solvent type, the microwave radiation time and the soil moisture and matrix. It was found that the MAEefficiency obtained by using acetone-hexane(volume ratio 1:1) was some equal to by using dichloromethane. The optimum MAEconditions for 2 g dry sample are as follows: adding water to 15% moisture, then adding 30 mLacetone-hexane(volume ratio 1:1), microwave power being at 600 W, pressure at the first stage(0.1～0.5 MPa) and microwave heating for 6 min. The extracts were detected by HPLC. The recoveries of naphthalene, acenaphthylene, fluorene, phenanthrene, anthracene, chrysene and benzopyrene were in the range of 82.2%—94.1%. Compared with the classical Soxhlet extraction, MAEis a more efficient, time-saving and solvent-saving method.

Key words: Microwave-assisted extraction(MAE), PAHs, Soil