| This thesis is an investigation of softwood chemical recovery condensates to identify compounds that are responsible for observed depressions of plasma testosterone in mummichog (Fundulus heteroclitus) exposed previously to solid phase extracts (SPE) of condensates in laboratory bioassays. Methodology was developed to fractionate the most potent of the extracts (SPE-2) using high pressure liquid chromatography (HPLC). Mummichog were exposed to HPLC fractions and inconsistencies were encountered in the potential of condensates and fractions to reduce testosterone between 3 repeated exposures. Condensates were collected over a 6-month period to evaluate the temporal variability of condensates and analytical methodologies. Nine extractives were confirmed and quantified with authentic standards by gas chromatography mass spectrometry (GC-MS) and flame photometric detection (GC-FPD). Temporal fluctuations of extractives were minimal across all samples collected over a 6-month period. Spiking experiments of confirmed extractives revealed substantial losses following HPLC fraction preparation, as a potentially major source of observed inconsistencies in fish exposures. Six candidate extractives were found to be associated with steroid depressions. Mass spectral interpretation indicated hydroxylated diterpenoids, sesquiterpenoids, and a lignin-derived stilbene. |
