| Ongoing research has demonstrated that specific environmental contaminants, commonly referred to as endocrine disrupting compounds (EDCs), can alter the functioning of the endocrine system by affecting normal growth, development and reproduction. In consequence, there is a fundamental need for innovative methods to improve the characterization of EDCs and their role in EDC-induced alterations in wildlife, specifically the changes in endogenous steroid profiles. The diverse physiochemical properties of steroids and EDCs impose inherent analytical limitations and thus current analytical methodologies for monitoring these compounds are often limited in scope and scale, limiting the overall understanding of contaminant-steroidogenesis interactions.New strategies that can simultaneously analyze a wide range of endogenous steroids in one chromatographic analysis would be a significant improvement over current methods. In the research reported here, application of chromatographic techniques such as gas and liquid chromatography, coupled with mass spectrometry (GC/MS, LC/MS), are shown to offer promising profiling capabilities in increasing the number of compounds detected and quantified. Several innovative sample preparation strategies, involving extraction and derivatization, were optimized and tailored to expand the dynamic range of compounds capable of being analyzed in a single analysis. In particular, novel extraction (solid-phase extraction (SPE) with several sorbents and solid-phase microextraction (SPME) with on-fiber derivatization) and derivatization (including microwave and solvent enhancement) strategies were explored and optimized. Sample preparation techniques were evaluated and compared in terms of yield, reproducibility, and overall analysis time.The overall profiling schemes were effective for the characterization of a diverse suite of environmental EDCs in surface water samples and steroids in alligator plasma. The analysis of endogenous steroids in the American alligator, in concert with the detection of EDCs from its natural (indigenous) water environment, provides a unique opportunity to correlate changes in the normal endocrine milieu in response to possible EDC exposure. |
