Application of sequential extraction with supercritical CO(2), subcritical H(2)O, and an H(2)O/CO(2) mixture for estimation of environmentally mobile heavy metal fractions in sediments.

Results from use of a new isolation procedure based on sequential extraction with supercritical CO(2), subcritical H(2)O, and an H(2)O/CO(2) mixture in the same supercritical fluid extractor have been compared with results from the BCR-recommended three-step sequential extraction procedure. The new procedure gives more detailed information about environmentally mobile fractions (water-soluble, bicarbonate-forming), and in less time (5-6 h), than the BCR procedure.