Extraction of polychlorinated dibenzo-p-dioxins and dibenzofurans from solid samples using the Randall technique

This study deals with a new sample extraction technique which minimizes pol lution in analytical laboratories whilst reducing sample preparation time a nd cost. The device uses the Randall technique for solid sample extraction, performed by immersion of the sample in boiling solvent. The fast solubili zation operated by the hot solvent leads to a sharp reduction in extraction time. This method was tested for the extraction of polychlorinated dibenzo -p-dioxins (PCDDs) and dibenzofurans (PCDFs) from different solid matrices using toluene as extractant, and compared with the conventional Soxhlet. Th e reduction in the extraction times (from 48 to 2 h) with an efficiency sim ilar to or higher than that afforded by the conventional Soxhlet technique indicates the suitability of this method. (C) 1999 Elsevier Science Ltd. Al l rights reserved.