EXTRACTION OF SEDIMENT-BOUND CHLORINATED ORGANIC-COMPOUNDS - IMPLICATIONS ON FATE AND HAZARD ASSESSMENT

Five methods were used for the extraction of hexachlorobutadiene and c hlorobenzenes from a contaminated estuarine sediment. The following ex traction methods were used: Soxhlet extraction, sonication and solvent extraction, sequential solvent extraction, saponification and solvent extraction, and supercritical fluid extraction. Soxhlet extraction re sulted in better contaminant extraction efficiency and reproducibility . Most of the problems associated with the extraction methods were rel ated to high water content and the inherent heterogeneity of the sedim ent samples. Drying and grinding of the sample greatly improved both e xtraction efficiency and reproducibility. Analyses of wet sieved and f ractionated sediment samples indicated that the contaminants are not e venly distributed throughout the sediment organic fraction but rather predominate in the larger particle sediment fraction. The implications of quantification difficulties of sediment contaminants on the enviro nmental fate and hazard assessment are discussed. Copyright (C) 1996 I AWQ.