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(46-25) Monitoring studies and fate modeling of alkylphenol ethoxylates and carboxylated metabolites in the Dutch coastal zone. Jonkers, Niels*,1, Laane, Remi1,2, De Voogt, Pim1, 1 University of Amsterdam, Nieuwe Achtergracht 166, Amsterdam, The Netherlands2 National Institute for Coastal and Marine Management, Kortenaerkade 1, The Hague, The Netherlands ABSTRACT- Alkylphenol ethoxylates (APEO), a group of nonionic surfactants, are of major environmental concern, because of their high production rate and the estrogenic effects of some of their possible metabolites. The fate of APEO and metabolites in the Dutch coastal zone was investigated in extensive sampling campaigns. Specific attention was paid to the new groups of metabolites which have recently been identified in laboratory degradation experiments, with either an oxidized ethoxy chain (alkylphenoxy ethoxy acetic acids, APEC) or both the ethoxy and alkylchain oxidized (CAPEC). Water and sediment samples were taken from highly industrialized areas as well as remote marine areas, including possible sources such as a sewage discharge, production platforms and main shipping routes. After solid phase extraction of the water and Soxhlet extraction of the sediments and suspended matter, reversed phase LC-ESI-MS was performed in + and - mode. APEO and NP were found in most sediments, including remote marine locations, up to a maximum concentration of 1080 ng g-1, while APEC metabolites are usually not present in the sediment. The APEC metabolites were present at higher concentrations than the APEO surfactants in the water phase, and their concentrations decreased much slower than APEO when going downstream in the Scheldt estuary, suggesting a formation of APEC out of APEO during transport through the estuary. The CAPEC metabolite group was not detected in the samples. Using the ECoS fate model for the Scheldt estuary, an estimation could be made of the contribution of biodegradation, the discharge of a highly industrialized canal and dilution of the river water to the concentration profiles of the surfactants and metabolites. Key words: alkylphenol ethoxylates, estuaries, monitoring, fate modeling |
