2003 IRISH SCIENTIST YEAR BOOK

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Athlone Institute of Technology
Antoinette Reid & James Roche
EDC trace analysis: what to look for, what not to miss!

Our environment - Nature's sink?

In recent years, there has been significant debate regarding exposures to ambient levels of endocrine disrupting chemicals (EDCs), which may be exerting adverse physiological effects on humans and wildlife populations in terms of fertility and sexual development. There is unequivocal evidence that a variety of oestrogen modulating chemicals capable of inducing oestrogenic effects are present in the environment. Environmental oestrogens refer to a range of anthropogenic and naturally occurring compounds that stimulate hormonal responses similar to the endogenous chemical 17 b-oestradiol. Presently, more than 50 non-steroidal anthropogenic chemicals are known to mimic the effects of the natural oestrogen, 17 b-oestradiol. Endogenous oestradiol binds to the oestrogen receptor, resulting in a receptor-ligand complex that interacts with the oestrogen response element of DNA, triggering a series of oestrogenic effects. Concerns have also arisen regarding environmental exposure to pharmaceutical oestrogens. Other chemicals such as PCBs, certain organopesticides, alkylphenols (from detergents), and phthalates (used as plasticisers) are also known to exert oestrogenic effects. Eleven chemicals of known or suspected oestrogenic potential were analysed for in this study - including alkylphenols, phthalates, and both natural and synthetic oestrogens.

Large towns and cities are known to contribute large amounts of polluting agents into aquatic systems as they release a variety of chemicals from industries, landfill and sewage effluent and sludges. Quantities of EDCs may be present in these wastes, leading to contamination of surface and ground water. Different techniques exist for extracting target contaminants from environmental matrices, and the methods used in this study utilise solid phase extraction (SPE) and solid phase microextraction (SPME) with subsequent chromatographic analysis by high performance liquid chromatography (HPLC). The overall objective of the study is to quantify trace levels of oestrogenic chemicals in selected Irish waterways and at the various stages of sewage treatment, and to develop sample preparation techniques as efficient methods for enrichment, which use little or no solvent. Selective partitioning is used to isolate analytes from the matrix, thereby helping to clean-up a sample before chromatographic analysis. The analytes in the sample bind non-covalently to the sorbent, whilst the impurities flush through. The analytes are subsequently eluted using an appropriate eluent. Samples are passed through long chain or medium chain sorbents for entrapment and clarification.

Another technique under examination is SPME. This may represent an improvement compared to SPE, as it is a rapid, solventless technique, relying on equilibrium partitioning and direct removal to the analytical system. Strategic sampling locations within the vicinity of landfill or sewage treatment plants (STPs) were chosen in the Midlands region to carry out extensive analysis for the presence of EDCs in leachate and effluent.

Contact: Antoinette Reid; E-mail: [email protected] ;
James Roche; E-mail: [email protected] ;
School of Science, Athlone Institute of Technology, Dublin Road, Athlone, Co. Westmeath; Tel: 353 (0)902 24400.