SUPERCRITICAL FLUID EXTRACTION OF POLYCHLORINATED DIBENZODIOXINS AND DIBENZOFURANS FROM SOIL SAMPLES

The extraction with supercritical CO2 is compared with the well known soxhlet method in order to reduce the required time for the extraction of soil samples. In the first step of this study extractions were carried out using sand spiked with three chloroorganic compounds. In order to explore the influence of three variables on the recovery of these compounds the statistical method of factorial design was applied. Using the results of this investigation the optimum extraction conditions from soil samples were determined by means of the sequential simplex method. In these experiments the extractable organic halogen (EOX) was used as a rough estimation parameter. Finally the extraction of two soil samples was conducted in order to determine the concentration of polychlorinated dibenzodioxins (PCDD) and polychlorinated dibenzofurans (PCDF). The results of the trials with supercritical CO2 were compared with the extraction data of the soxhlet method and they correspond well.