FOCUSED MICROWAVE-ASSISTED EXTRACTION (FM AE) OF POLYNUCLEAR AROMATIC-HYDROCARBONS FROM CONTAMINATED SOIL - ROLE OF ACETONE AND WATER-CONTENT IMPACT OIL MICROWAVE EFFICIENCY

Focused microwave energy was used to extract 15 PAH from contaminated soil. Microwave irradiation was used to avoid the use of solvents char acterized bg a small dielectric constant. A water and solvent mixture with different polarities was considered to improve the microwave effe ct. The decrease in solvatation power caused by the addition of aceton e into methylene chloride, is compensated for by the improvement in mi crowave efficiency. The necessity of working with an homogeneous extra ctant system was demonstrated, and acetone appeared to be an essential parameter in soil sample extraction. Moreover, the variability of the results depended on the way water was introduced into the system. Thu s, matrix moistening is more suitable than solvent hydration. Ten minu tes of FMAE gave comparable results to those obtained after eight hour s of Soxhlet extraction, with greater reproducibility.