title: Identification of compounds associated with testosterone depressions in fish exposed to bleached kraft pulp and paper mill chemical recovery condensates.
abstract: In previous experiments, bleached kraft chemical recovery condensates generated during softwood pulp production have been identified as a primary source of substances causing testosterone depressions in mummichog (Fundulus heteroclitus). Recent toxicity identification evaluations have encountered inconsistencies in the potential of condensates and fractions to reduce steroid concentrations between three repeated exposures. To assess the sources of these inconsistencies, temporal assessments of condensate extractives and analytical methodologies were evaluated. Condensates were collected during a six-month period, extracted by solid-phase extraction (SPE), and analyzed by gas chromatography-mass spectrometry and gas chromatography-flame photometric detection. All unique extractives were cataloged by mass spectra, peak area, and gas chromatographic retention time, and nine were confirmed and quantified against authentic standards. Confirmed components included phenolic guaiacyl-based lignin degradation products, sulfur (S9), three diterpenoids, and a dimethoxy stilbene. Concentrations of confirmed condensate extractives were consistent in all samples collected. Spiking experiments of confirmed extractives revealed substantial losses following high-pressure liquid chromatographic fractionation and three different methods of fraction preparation. In an effort to propose chemical classes associated with biological activity, all unique condensate extractives in previously established bioactive and inactive fractions were classified based on their potential to depress testosterone in mummichog. Of 39 unique components in bioactive SPE extracts of condensates, six were associated with hormonal activity. Mass spectral interpretation indicated hydroxylated diterpenoids, sesquiterpenoids, and a lignin-derived stilbene as classes of chemicals associated with steroid depressions.
authors.affiliation: Department of Environmental Biology, University of Guelph, Bovey Building, Gordon Street, Guelph, Ontario N1G 2W1, Canada. abbab@hotmail.com
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Belknap
authors.forename: Keith R
authors.initials: KR
authors.lastname: Solomon
authors.forename: Deborah L
authors.initials: DL
authors.lastname: MacLatchy
authors.forename: Monique G
authors.initials: MG
authors.lastname: Dubé
authors.forename: L Mark
authors.initials: LM
authors.lastname: Hewitt
mesh_terms: D000818:Animals; D005399:Fishes / Q000378:metabolism*; D007220:Industrial Waste / Q000009:adverse effects*; D008297:Male; D015394:Molecular Structure; D010209:Paper; D013739:Testosterone / Q000378:metabolism*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000009:adverse effects* / Q000032:analysis; D014877:Water Pollution, Chemical / Q000009:adverse effects / Q000032:analysis; D014934:Wood
chemical_list: D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D013739:Testosterone