Supercritical fluid extraction of water samples containing ultratrace amounts of organic micropollutants

A true solventless off-line supercritical fluid extraction (SFE) method has been developed, which does not use organic solvents for trapping and for washing out of analytes. Determination of polynuclear aromatic hydrocarbons, chlorinated pesticides, and polychlorinated biphenyls in aqueous solutions based on their direct SFE extraction and on off-line solventless SFE/gas chromatography coupling has been done. This new method has a detection limit at the parts per billion/parts per trillion level. For the ultralow concentration level of 0.1-1 ppt, direct SFE from water was more accurate, faster, and more reproducible than conventional sample preparation methods based on micro-liquid/liquid extraction and solid-phase extraction. (C) 1999 John Wiley & Sons, Inc.