SOLID-PHASE EXTRACTION OF POLYCHLORODIBENZODIOXINS AND POLYCHLORODIBENZOFURANS DISSOLVED IN PARTICLE-FREE WATER CONTAINING HUMIC SUBSTANCES

The effect of dissolved organic materials, such as humic acids, on the recovery of PCDDs and PCDFs from particle-free water is demonstrated. Experiments are carried out in a range of concentrations and using materials for water container that allow a correct evaluation of the binding properties of humic acids toward the compounds of interest. A method to destroy the humic acids prior to the preconcentration procedure is described, which allows to obtain good recovery of PCDDs and PCDFs from particle-free water. Examples of application to river water spiked with 1 ng/L of PCDDs and PCDFs are reported to show the applicability of the method described to real samples in the case of severe water pollution.