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(453) The Persistence of Non-Ionic Surfactants and their Primary Degradation Products in the Marine and Freshwater Environment. Ikonomou, Michael1, Macdonald, Robie1, Shang, Dayue2, Natasha, Hoover1, 1 2 ABSTRACT- Alkylphenol polyethoxylates (APEOs) are the second largest class of nonionic surfactants in commercial production in North America. Some of these surfactants biodegrade before reaching the environment when wastewater is processed via treatment plants which often remove more than 95% of the higher ethoxylates through secondary treatment. The degradation of APEOs in the environment has been the subject of disagreement, contradiction, and controversy for many years. Recent concern has focused on APEOs as potential endocrine disrupters. Considering toxicity, the large production volumes and likely persistence, APEOs - especially NPEOs (nonylphenol ethoxylates) - have emerged as a leading issue in Europe where a phased withdrawal for many uses has been proposed by a number of EU countries. Over the past few years we have been interested on the fate and distribution of NPEOs in the marine environment. We developed a novel analytical method based on LC/ESI-MS for the quantitative determination of NPEOs in environmental matrices. We applied the method to determine individual oligomers (n = 1 to 19) of NPEO in marine and freshwater sediment cores and surface grabs collected near a Vancouver municipal sewage outfall and near discharge sites from pulp and paper mills. Our data showed that over half the NPnEO inventory in marine sediments resides in ethoxylates of chain length greater than n = 2 suggesting that analyses limited to short-chain ethoxylates (n = 2) are under-reporting total NPnEO by a factor of two. The NPnEO vertical profiles and oligomer distributions in dated sediment cores suggest that little degradation occurs once these compounds enter the sediments. The lack of change in NPnEO oligomer distribution with age suggests that degradation by chain shortening does not occur significantly. In this presentation we will also present the spatial and temporal distribution of linear-alcohol-ethoxylates in the same samples that were measured in parallel with the NPEOs. Key words: Non-Ionic Surfactants , nonylphenol ethoxylates, linear-alcohol-ethoxylates, LC/ESI-MS |
