title: Effects-Directed Analysis of Dissolved Organic Compounds in Oil Sands Process-Affected Water.
abstract: Acute toxicity of oil sands process-affected water (OSPW) is caused by its complex mixture of bitumen-derived organics, but the specific chemical classes that are most toxic have not been demonstrated. Here, effects-directed analysis was used to determine the most acutely toxic chemical classes in OSPW collected from the world's first oil sands end-pit lake. Three sequential rounds of fractionation, chemical analysis (ultrahigh resolution mass spectrometry), and acute toxicity testing (96 h fathead minnow embryo lethality and 15 min Microtox bioassay) were conducted. Following primary fractionation, toxicity was primarily attributable to the neutral extractable fraction (F1-NE), containing 27% of original organics mass. In secondary fractionation, F1-NE was subfractionated by alkaline water washing, and toxicity was primarily isolated to the ionizable fraction (F2-NE2), containing 18.5% of the original organic mass. In the final round, chromatographic subfractionation of F2-NE2 resulted in two toxic fractions, with the most potent (F3-NE2a, 11% of original organic mass) containing predominantly naphthenic acids (O2(-)). The less-toxic fraction (F3-NE2b, 8% of original organic mass) contained predominantly nonacid species (O(+), O2(+), SO(+), NO(+)). Evidence supports naphthenic acids as among the most acutely toxic chemical classes in OSPW, but nonacidic species also contribute to acute toxicity of OSPW.
authors.affiliation: Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada.
authors.forename: Garrett D
authors.initials: GD
authors.lastname: Morandi
authors.affiliation: Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada.
authors.forename: Steve B
authors.initials: SB
authors.lastname: Wiseman
authors.affiliation: Division of Analytical and Environmental Toxicology, University of Alberta , Edmonton, Alberta T6G 2G3, Canada.
authors.forename: Alberto
authors.initials: A
authors.lastname: Pereira
authors.affiliation: Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada.
authors.forename: Rishikesh
authors.initials: R
authors.lastname: Mankidy
authors.affiliation: Division of Analytical and Environmental Toxicology, University of Alberta , Edmonton, Alberta T6G 2G3, Canada.
authors.forename: Ian G M
authors.initials: IG
authors.lastname: Gault
authors.affiliation: Division of Analytical and Environmental Toxicology, University of Alberta , Edmonton, Alberta T6G 2G3, Canada.
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Martin
authors.affiliation: Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B3, Canada.|Department of Veterinary Biomedical Sciences, University of Saskatchewan , Saskatoon, Saskatchewan S7N 5B4, Canada.|Department of Zoology, and Center for Integrative Toxicology, Michigan State University , East Lansing, Michigan 48824, United States.|Department of Biology & Chemistry and State Key Laboratory for Marine Pollution, City University of Hong Kong , Kowloon, Hong Kong Special Administrative Region (SAR), People's Republic of China.|School of Biological Sciences, The University of Hong Kong , Hong Kong SAR, People's Republic of China.|State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing 210023, People's Republic of China.|Department of Biology, Hong Kong Baptist University , Hong Kong SAR, People's Republic of China.
authors.forename: John P
authors.initials: JP
authors.lastname: Giesy
mesh_terms: D000416:Alberta; D048908:Aliivibrio fischeri / Q000187:drug effects; D000818:Animals; D002264:Carboxylic Acids / Q000032:analysis / Q000633:toxicity; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003530:Cyprinidae / Q000196:embryology; D004625:Embryo, Nonmammalian / Q000187:drug effects; D006838:Hydrocarbons; D013058:Mass Spectrometry / Q000379:methods; D061329:Oil and Gas Fields; D009930:Organic Chemicals / Q000032:analysis / Q000633:toxicity; D023382:Toxicity Tests, Acute / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000633:toxicity*
chemical_list: D002264:Carboxylic Acids; D006838:Hydrocarbons; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; C006647:asphalt; C046170:naphthenic acid