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 pollution in analytical laboratories whilst reducing sample preparation time and cost. The device uses the Randall technique for solid sample extraction, performed by immersion of the sample in boiling solvent. The fast solubilization 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. The reduction in the extraction times (from 48 to 2 h) with an efficiency similar to or higher than that afforded by the conventional Soxhlet technique indicates the suitability of this method.