SENSITIVITY ENHANCEMENT IN DYNAMIC OFF-LINE SUPERCRITICAL-FLUID EXTRACTION

A method for analytical supercritical fluid extraction in ''off-line'' mode was developed with the aim of obtaining maximum sensitivity, i.e . maximally concentrated solute solutions after extraction without fur ther concentration steps. Dry deposition on the inner capillary wall w as used, followed by rinsing of the trapped solutes using a minimum vo lume of the solvent. For the case of an inert support (glass beads) sp iked with fluoranthene, the reproducible minimal volume of the solvent was determined and the influence of flow velocity in the trapping cap illary was studied.