Salmonid smolt caudal fin and liver transcriptome responses to low sulfur marine diesel and high sulfur fuel oil water accommodated fractions for assessing oil spill effects in marine environments.

The environmental impact of oil spills is a critical concern, particularly pertaining to low sulfur marine diesel (LSMD) and high sulfur fuel oil (HSFO) that are commonly involved in coastal spills. Although transcriptomic biomonitoring of sentinel animals can be a powerful tool for assessing biological effects, conventional methods utilize lethal sampling to examine the liver. As a non-lethal alternative, we have previously shown salmonid caudal fin cyp1a1 is significantly responsive to LSMD-derived toxicants.

Method development for forensic oil identification by direct analysis in real time time-of-flight mass spectrometry.

The current well-established chromatography and mass spectrometry based oil spill identification procedures, such as those outlined by the European Committee for Standardization, are highly reliable as methods, highly defensible in the court of law, and widely applicable to the majority of oil spill situations. Nevertheless, the methodology is time consuming and labour intensive, which may not be ideal when dealing with an emergency oil spill situation. In this study, direct analysis in real time time-of-flight mass spectrometry (DART/TOFMS) was used to successfully develop an efficient oil identification method.

Long chain fatty acids analysis of intertidal biofilm by direct injection liquid chromatography time of flight mass spectrometry.

The critical importance of mono- and polyunsaturated fatty acids (FAs) in a variety of biological functions, including animal nutrition and as an environmental stress monitor, is well recognized. However, while methods exist for monitoring of fatty acids, few are specific either to the profile of a microphytobenthos matrix or practical in application to multiple, diverse intertidal biofilm sample sets. In the current study, a sensitive liquid chromatography (LC) quadrupole time of flight mass spectrometry (QTOF) method was developed for the quantitative analysis of 31 FAs specific to intertidal biofilm, a thin mucilaginous layer of microalgae, bacteria, and other organisms on the surface of coastal mudflats, which provide a rich source of FAs for migratory birds.

Enhancement of oil forensic methodology through the addition of polycyclic aromatic nitrogen heterocycle biomarkers for diagnostic ratios.

Current oil spill forensic identification of source oils relies upon hydrocarbon biomarkers resistant to weathering. This international technique was developed by the European Committee for Standardization (CEN), under EN 15522-2 Oil Spill Identification guidelines. The number of biomarkers have expanded at pace with technological advances, while distinguishing new biomarkers becomes more challenging due to interference of isobaric compounds, matrix effects, and high cost of weathering experiments.

Dynamic cyp1a1 transcript responses in the caudal fin of coho salmon (Oncorhynchus kisutch) smolts to low sulfur marine diesel water accommodated fraction exposures and depuration.

Oil spills that occur in high traffic coastal environments can have profound consequences for the health of marine ecosystems and the commercial and social interests that are dependent upon these habitats. Given that the global reliance on marine fuels is not abating, it is imperative to develop sensitive and robust tools to monitor oil contamination and remediation in a timely manner. Such tools are increasingly important for ascertaining the immediate and long-term effects of oil contamination on species of interest and local habitats as water-soluble components of oils, such as polycyclic aromatic hydrocarbons (PAHs), can persist post-remediation.

Advancement in oil forensics through the addition of polycyclic aromatic sulfur heterocycles as biomarkers in diagnostic ratios.

In current oil spill forensics, diagnostic ratios of hydrocarbon biomarker responses are commonly used to compare oil spill samples to source materials in order to determine the identity of the oil. This well recognized procedure was developed by the European Committee for Standardization (CEN) with corresponding published EN 15522-2 Oil Spill Identification guidelines. However, it is further recognized that weathering can have a negative effect on some of the biomarkers used in the analysis, leading to decreased confidence in the result.

A rapid gas chromatography quadrupole time-of-flight mass spectrometry method for the determination of polycyclic aromatic hydrocarbons and sulfur heterocycles in spilled crude oils.

Spilled crude oil samples contain various toxic compounds including polycyclic aromatic hydrocarbons (PAHs) as well as sulfur heterocycles (PASHs) and their related alkylated forms (APAHs and APASHs). In this study, a method was successfully developed employing a gas chromatography quadrupole time-of-flight (GC-QToF) mass spectrometer to quantitatively analyze both PAHs/APAHs and PASHs/APASHs in these samples. With GC-QToF, the monoisotopic mass of the compounds is distinguished, allowing the PASHs/APASHs to be extracted separately from the PAHs/APAHs in crude oil.

Trace analysis of resin acids in surface waters by direct injection liquid chromatography time of flight mass spectrometry and triple quadrupole mass spectrometry.

A rapid and sensitive liquid chromatography (LC) quadrupole time of flight (QTOF) method has been developed for the determination of resin acid concentrations in aqueous pulp and paper effluent related samples. Calibration R of ≥0.995 for twelve resin acids, namely dehydroabietic, 8(14)-abietenic, dihydroisopimaric, levopimaric, neoabietic, pimaric, sandaracopimaric, abietic, isopimaric, palustric, chlorodehydroabietic, and dichlorodehydroabietic acids, was demonstrated in the range 1 µgL to 40 µgL.

Dioctyl Sodium Sulfosuccinate as a Potential Endocrine Disruptor of Thyroid Hormone Activity in American bullfrog, Rana (Lithobates) catesbeiana, Tadpoles.

The thyroid hormones, thyroxine (T) and triiodothyronine (T), are required to regulate complex developmental processes in vertebrates and are highly sensitive to endocrine-disrupting compounds. Previous studies demonstrate that dioctyl sodium sulfosuccinate (DOSS), a common constituent of pharmaceuticals, cosmetics, and food products, disrupts canonical signaling of adipocyte differentiation by binding a nuclear hormone receptor in the same superfamily as thyroid hormone (TH) receptors. The present study was designed to determine whether DOSS is capable of disrupting TH signaling using the American bullfrog, Rana (Lithobates) catesbeiana-a cosmopolitan frog species that undergoes TH-dependent metamorphosis to transition from an aquatic tadpole to a terrestrial juvenile frog.

Enhanced analysis of weathered crude oils by gas chromatography-flame ionization detection, gas chromatography-mass spectrometry diagnostic ratios, and multivariate statistics.

Artificially weathered crude oil "spill" samples were matched to unweathered suspect "source" oils through a three-tiered approach as follows: Tier 1 gas chromatography-flame ionization detection (GC/FID), Tier 2 gas chromatography-mass spectrometry (GC/MS) diagnostic ratios, and Tier 3 multivariate statistics. This study served as proof of concept for a promising and new method of crude oil forensics that applies principal component analysis (PCA) and partial least squares discriminant analysis (PLSDA) in tandem with traditional forensic oil fingerprinting tools to confer additional confidence in challenging oil spill cases. In this study, weathering resulted in physical and chemical changes to the spilled oils, thereby decreasing the reliability of GC/FID and GC/MS diagnostic ratios in source attribution.

Long-term spatial and temporal trends, and source apportionment of polycyclic aromatic compounds in the Athabasca Oil Sands Region.

We investigated the spatio-temporal trends of polycyclic aromatic compounds (PACs) deposition in the Athabasca Oil Sands Region (AOSR) between 2008 and 2017, and applied source apportionment tools to assess sources using snowpacks. Estimated PAC mass deposition was significantly correlated with crude oil production (R = 0.48, p = 0.

Tiered approach to long-term weathered lubricating oil analysis: GC/FID, GC/MS diagnostic ratios, and multivariate statistics.

Frequent small-scale environmental releases of lubricating (lube) oils have deleterious effects on aquatic ecosystems. In the event of a spill, oil fingerprinting is critical to source attribution, clean-up procedures, and liability assignment. Oil forensic investigations are particularly challenging when oils are weathered over an extended period of time, as a large number of biomarkers become lost and the chemical composition changes significantly from its source.

A one-century sedimentary record of N- and S-polycyclic aromatic compounds in the Athabasca oil sands region in Canada.

The atmospheric deposition of polycyclic aromatic compounds (PACs) is considered a major pathway to isolated lakes and bogs in the Athabasca oil sands region (AOSR), Canada. However, the suite of PACs measured has been limited. We report the detailed depositional history of nitrogen and sulphur heterocyclic PACs using a Pb dated sediment core (1914-2015) near major developments in the AOSR.

Polycyclic aromatic compounds (PACs) in the Canadian environment: A review of sampling techniques, strategies and instrumentation.

A wide variety of sampling techniques and strategies are needed to analyze polycyclic aromatic compounds (PACs) and interpret their distributions in various environmental media (i.e., air, water, snow, soils, sediments, peat and biological material).

Enhanced marine monitoring and toxicity study of oil spill dispersants including Corexit EC9500A in the presence of diluted bitumen.

Observations made for the analysis of the oil spill dispersant tracer dioctyl sulfosuccinate (DOSS) during LC50 toxicity testing, highlighted a stability issue for this tracer compound in seawater. A liquid chromatography high-resolution quadrupole time-of-flight mass spectrometry (LC/QToF) was used to confirm monooctyl sulfosuccinate (MOSS) as the only significant DOSS breakdown product, and not the related isomer, 4-(2-ethylhexyl) 2-sulfobutanedioate. Combined analysis of DOSS and MOSS was shown to be applicable to monitoring of spill dispersants Corexit® EC9500A, Finasol OSR52, Slickgone NS, and Slickgone EW.

Diagnostic Ratio Analysis: A New Concept for the Tracking of Oil Sands Process-Affected Water Naphthenic Acids and Other Water-Soluble Organics in Surface Waters.

A diagnostic ratio forensics tool, similar to that recognized internationally for oil spill source identification, is proposed for use in conjunction with existing LC/QToF quantitative methodology for bitumen-derived water-soluble organics (WSOs). The concept recognizes that bitumen WSOs bear a chemical skeletal relationship to stearane and hopane oil biomarkers. The method uses response ratios for 50 selected WSOs compared between samples by their relative percent difference and adopted acceptance criteria.

Chemotyping and identification of protected Dalbergiatimber using gas chromatography quadrupole time of flight mass spectrometry.

The international trade in illegally logged and environmentally endangered timber has spurred enforcement agencies to seek additional technical procedures for the identification of wood species. All Dalbergia species are listed under the Convention on International Trade in Endangered Species (CITES) which is the reason this genus was chosen for study. Multiple sources of the heartwood from different Dalbergia species were extracted and chromatographic profiles collected by gas chromatography with high resolution quadrupole Time of Flight mass spectrometry (GC/QToF).

Improved oil spill dispersant monitoring in seawater using dual tracers: Dioctyl and monoctyl sulfosuccinates sourced from corexit EC9500A.

A high resolution mass spectrometry method was developed for the environmental impact monitoring of oil spill dispersants. Previously reported instability of dioctyl sulfosuccinate (DOSS) dispersant tracer was addressed by the new procedure. The method monitors both DOSS and its degradation product, monooctyl sulfosuccinate (MOSS), by liquid chromatography time-of-flight mass spectrometry.

Deposition and Source Identification of Nitrogen Heterocyclic Polycyclic Aromatic Compounds in Snow, Sediment, and Air Samples from the Athabasca Oil Sands Region.

Polycyclic aromatic compounds (PACs) can have multiple sources in the Athabasca Oil Sands Region (AOSR). The current study was designed to identify and explore the potential of nitrogen heterocyclic PACs (NPACs) as source indicators in snowpack, lake sediment and passive air samples from the AOSR during 2014-2015. Source samples including petroleum coke (petcoke), haul road dust, and unprocessed oil sands were also analyzed.

Evaluation of Gene Bioindicators in the Liver and Caudal Fin of Juvenile Pacific Coho Salmon in Response to Low Sulfur Marine Diesel Seawater-Accommodated Fraction Exposure.

Low sulfur marine diesel (LSMD) is frequently involved in coastal spills and monitoring ecosystem damage, and the effectiveness of cleanup methods remains a challenge. The present study investigates the concentration and composition of polycyclic aromatic hydrocarbons (PAHs) dispersed in LSMD seawater accommodated fractions (WAFs) and assesses the effects of exposure on juvenile coho salmon ( Onchorhynchus kisutch). Three WAFs were prepared with 333, 1067, and 3333 mg/L LSMD.

Acute toxicity of Corexit EC9500A and assessment of dioctyl sulfosuccinate as an indicator for monitoring four oil dispersants applied to diluted bitumen.

The present study investigated oil dispersant toxicity to fish species typical of the cooler regions of Canada, together with less well-documented issues pertaining to oil dispersant monitoring. The oil dispersant toxicity of Corexit EC9500A was assessed for the freshwater fish species rainbow trout and the seawater species coho, chinook, and chum, with a final median lethal concentration (LC50) acute lethality range between 35.3 and 59.

Toxicity of naphthenic acids to invertebrates: Extracts from oil sands process-affected water versus commercial mixtures.

The toxicity of oil sands process-affected water (OSPW) has been primarily attributed to polar organic constituents, including naphthenic acid fraction components (NAFCs). Our objective was to assess the toxicity of NAFCs derived from fresh and aged OSPW, as well as commercial naphthenic acid (NA) mixtures. Exposures were conducted with three aquatic species: Hyalella azteca (freshwater amphipod), Vibrio fischeri (marine bacterium, Microtox assay), and Lampsilis cardium (freshwater mussel larvae (glochidia)).

A traceable reference for direct comparative assessment of total naphthenic acid concentrations in commercial and acid extractable organic mixtures derived from oil sands process water.

The advantage of using naphthenic acid (NA) mixtures for the determination of total NA lies in their chemical characteristics and identification of retention times distinct from isobaric interferences. However, the differing homolog profiles and unknown chemical structures of NA mixtures do not allow them to be considered a traceable reference material. The current study provides a new tool for the comparative assessment of different NA mixtures by direct reference to a single, well-defined and traceable compound, decanoic-d acid.

Sensitivity of walleye (Sander vitreus) and fathead minnow (Pimephales promelas) early-life stages to naphthenic acid fraction components extracted from fresh oil sands process-affected waters.

Unconventional oil production in Alberta's oil sands generates oil sands process-affected water (OSPW), which contains toxic constituents such as naphthenic acid fraction components (NAFCs). There have been few studies examining effects of NAFC exposure over long periods of early-life stage development in fish. Here we examined the effects of NAFCs extracted from OSPW to embryo-larval fathead minnow, exposed for 21 days.

Trace analysis of total naphthenic acids in aqueous environmental matrices by liquid chromatography/mass spectrometry-quadrupole time of flight mass spectrometry direct injection.

A rapid and sensitive liquid chromatography quadrupole time of flight method has been established for the determination of total naphthenic acid concentrations in aqueous samples. This is the first methodology that has been adopted for routine, high resolution, high throughput analysis of total naphthenic acids at trace levels in unprocessed samples. A calibration range from 0.