ANALYTICAL-SCALE EXTRACTION OF ENVIRONMENTAL-SAMPLES USING SUPERCRITICAL FLUIDS

Analytical-scale supercritical fluid extraction (SFE) is a rapidly-developing method for the extraction of organic analytes from environmental solids including soils, sediments, air particulates, and sorbent resins. SFE virtually eliminates the need for liquid solvents, and 10 to 90-minute SFE extractions can yield recoveries of organic pollutants which compare favorably with those obtained using several hours of conventional liquid solvent extraction. Even though SFE is relatively simple to perform, the development of routine SFE methods is hampered because the physical and chemical mechanisms which control ultimate recoveries are poorly understood. To develop a quantitative SFE method, the physicochemical processes which control the partitioning of the analytes from the matrix into the extraction fluid, and the efficient collection of the extracted analytes from the supercritical fluid must be controlled. Approaches to the development of quantitative SFE methods for organic pollutants from environmental samples including soils and sediments, air particulates, sorbent resins, and water will be discussed.