Extraction of Nonylphenol and Nonylphenol Ethoxylates from River Sediments: Comparison among different Extraction Techniques

Five different extraction techniques (Soxhlet, automated Randall, accelerated solvent extraction, microwave assisted solvent extraction and extraction with a surfactant solution) for the determination of NP and NPEOs in river sediments have been evaluated in this study. All the techniques were applied to the same three samples collected from northern Italian rivers. The analyses have been performed with two RP columns, with different stationary reversed phases: a classical C-18 phase and a hexyl-phenyl one. Recoveries and the reproducibilities of the different extraction techniques are comparable and all methods give reliable results. The variance of the results is dominated by the variance in sample homogeneity, sample preparation and chromatographic analysis. The choice between the methods can be made on the basis of cost and safety characteristics of each technique. Preliminary results on an aqueous based extraction method with a surfactant solution (Tween-80) and its application to sediment and worm tissue analysis are also presented