title: Characterization of oil sands process-affected waters by liquid chromatography orbitrap mass spectrometry.
abstract: Recovery of bitumen from oil sands in northern Alberta, Canada, occurs by surface mining or in situ thermal recovery, and both methods produce toxic oil sands process-affected water (OSPW). A new characterization strategy for surface mining OSPW (sm-OSPW) and in situ OSPW (is-OSPW) was achieved by combining liquid chromatography with orbitrap mass spectrometry (MS). In electrospray positive and negative ionization modes (ESI(+)/ESI(-)), mass spectral data were acquired with high resolving power (RP > 100,000-190,000) and mass accuracy (<2 ppm). The additional chromatographic resolution allowed for separation of various isomers and interference-free MS(n) experiments. Overall, ∼3000 elemental compositions were revealed in each OSPW sample, corresponding to a range of heteroatom-containing homologue classes: Ox (where x = 1-6), NOx (where x = 1-4), SOx (where x = 1-4), NO₂S, N, and S. Despite similarities between the OSPW samples at the level of heteroatom class, the two samples were very different when considering isomer patterns and double-bond equivalent profiles. The chromatographic separations also allowed for confirmation that, in both OSPW samples, the O₂ species detected in ESI(-) (i.e., naphthenic acids) were chemically distinct from the corresponding O₂ species detected in ESI(+). In comparison to model compounds, tandem MS spectra of these new O₂ species suggested a group of non-acidic compounds with dihydroxy, diketo, or ketohydroxy functionality. In light of the known endocrine-disrupting potential of sm-OSPW, the toxicity of these O₂ species deserves attention and the method should be further applied to environmental forensic analysis of water in the region.
authors.affiliation: Division of Analytical and Environmental Toxicology, Department of Lab Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2G3, Canada.
authors.forename: Alberto S
authors.initials: AS
authors.lastname: Pereira
authors.forename: Subir
authors.initials: S
authors.lastname: Bhattacharjee
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Martin
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods*; D010578:Petroleum; D012822:Silicon Dioxide; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D010578:Petroleum; D014874:Water Pollutants, Chemical; D012822:Silicon Dioxide