SUPERCRITICAL-FLUID EXTRACTION IN ENVIRONMENTAL-ANALYSIS

Supercritical fluid extraction (SFE), usually with carbon dioxide and often with a modifier. is a rapid, selective and convenient method for sample clean-up in environmental analysis. Three inter-related factor s influence analyte recovery in SFE: solubility in the fluid, diffusio n through the matrix and adsorption in the matrix. SFE may be coupled on-line to various analytical methods: gas, liquid and supercritical f luid chromatography. A wide range applications of SFE from environment al samples is described: hydrocarbons, chlorobenzenes and chlorobiphen yls, dioxins and chlorinated pesticides, herbicides and ionic surfacta nts. Organic compounds may be concentrated from air and water and extr acted from adsorbents by SFE. Direct SFE from water is also possible.