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Summary Endospore‐forming bacteria make up an important and numerically significant component of microbial communities in a range of settings including soils, industry, hospitals and marine sediments extending into the deep subsurface. Bacterial endospores are non‐reproductive structures that protect DNA and improve cell survival during periods unfavourable for bacterial growth. An important determinant of endospores withstanding extreme environmental conditions is 2,6‐pyridine dicarboxylic acid (i.e. dipicolinic acid, or DPA), which contributes heat resistance. This study presents an improved HPLC‐fluorescence method for DPA quantification using a single 10‐min run with pre‐column Tb3+ chelation. Relative to existing DPA quantification methods, specific improvements pertain to sensitivity, detection limit and range, as well as the development of new free DPA and spore‐specific DPA proxies. The method distinguishes DPA from intact and recently germinated spores, enabling responses to germinants in natural samples or experiments to be assessed in a new way. DPA‐based endospore quantification depends on accurate spore‐specific DPA contents, in particular, thermophilic spores are shown to have a higher DPA content, meaning that marine sediments with plentiful thermophilic spores may require spore number estimates to be revisited. This method has a wide range of potential applications for more accurately quantifying bacterial endospores in diverse environmental samples.

During the Deepwater Horizon (DwH) oil spill, an excessive production of marine snow was observed, and it was estimated that as much as 14% of the oil was transferred to the ocean floor by MOSSFA (Marine Oil Snow Sedimentation and Flocculent Accumulation). MOSSFA is an important pathway of transferring oil to the ocean floor. We performed experiments at laboratory scale in 15 aquaria, representing 5 exposures of marine snow with or without oil, only oil, and controls with only clay or sediment. We developed a method to produce artificial marine snow, which resembles the natural marine snow. Results showed 40% less biodegradation of alkanes in “marine snow with oil” compared to “only oil.” Most probably, this is due to preferred biodegradation of marine snow organics comparing to oil alkanes. Biodegradation of marine snow reduces the dissolved oxygen concentration, which might result in anaerobic conditions in the sediment layer. This finding can be projected to a potential ocean floor effect.

The world’s energy system is still dominated by fossil fuels. While there is a rapid reduction in the cost of renewable energy and the environmental costs of continued carbon dioxide emissions from fossil fuel recovery and use are well understood, current economic, infrastructure and political constraints sustain the fossil fuel enterprise as a dominant component of the energy system. Though routes to decarbonizing fossil fuel use, such as carbon capture and storage, have been proposed and have been demonstrated at commercial scale, current CCS CO2 storage quantities are very small and no large-scale practical route to providing fossil fuel energy, without the CO2 emissions attendant with fuel production and use has been proposed. Here we look at some of the boundary conditions and possible routes to production of emissions free energy from fossil fuels, and specifically petroleum reservoirs. Focusing on the production of electrical power we look at possible applications of microbially mediated hydrocarbon oxidation, coupled to a range of energy harvesting strategies, to the provision of electrical power at surface at a range of scales suitable for grid power provision, powering upstream oilfield facilities or for powering in situ sensing and exploration systems. We also ask the question, even if practical, would direct production of electrical power from oil and gas fields be a politically and economically sensible strategy as part of the energy transition away from traditional fossil fuel use.

The invention provides a membrane-free redox cell utilizing auxiliary electrodes that facilitate fast charging and discharging of anolyte and catholyte for electrochemical energy storage. The anode and cathode chambers are ionically separated, and electrically connected through a conductor joining auxiliary electrodes comprised of a redox material. In use, charging/discharging of the galvanic cell takes place between primary electrodes, and the redox material is immersed in the electrolyte in both anode and cathode chambers.

Comprehensive two-dimensional gas chromatography (GC × GC) was used to explore and compare the chemical complexity of oil released from the Deepwater Horizon (DWH) disaster in 2010 and the Ixtoc I ...

Despite the ongoing push to transition global economy away from fossil fuels, large volumes of crude oil and petroleum products will continue to be produced and transported in marine settings in the forseeable future. With that comes an inherent risk of marine oil spills, both small-scale, operational spills occurring on daily basis, and large catastrophic events, such as deepwater blowouts on oil platforms, or ship/boat collision incidents. The common adage of spill science states, “every spill is different,” which reflects the complexity of variables that must be considered, both during the initial spill response and, in longer term, for damage assessment and monitoring. These include source(s) and type(s) of spilled crude oil or petroleum product, abiotic and biotic transformations (weathering) of a spill and its ultimate fate, as well as the impacts of oil components and their transformation products on different marine ecosystem elements (pelagic, benthic, coastal, etc.). In the last several decades, important advancements have occurred in oil spill science, in large part driven by new developments in analytical instrumentation and methods, for instance, the multidimensional chromatography and high-resolution mass spectrometry, to name a few. These advancements were successfully applied during major recent spills, most notably the 2010 Deepwater Horizon blowout, and have also been used to reassess some of the historic oil spill incidents, for example, the 1979 Ixtoc-1 spill. This chapter will showcase a selection of the most relevant novel insights that came out from various oil spill studies conducted in the past 10 years.

This work introduces a novel analytical chemistry method potentially applicable to the study of archaeological starch residues. The investigation involved the laboratory synthesis of model Maillard reaction mixtures and their analysis through Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR-MS). Thus, starch from sixteen plant species were matured while reacting it with the amino acid glycine. The FTICR-MS analysis revealed > 5,300 molecular compounds, with numerous unique heteroatom rich compound classes, ranging from 20 (Zea mays) to 50 (Sorghum bicolor). These classes were investigated as repositories of chemical structure retaining source and process-specific character, linked back to botanical provenance. We discussed the Maillard reaction products thus generated, a possible pathway for the preservation of degraded starch, while also assessing diagenetic recalcitrance and adsorption potential to mineral surfaces. In some cases, hydrothermal experimentation on starches without glycine reveals that the chemical complexity of the starch itself is sufficient to produce some Maillard reaction products. The article concludes that FTICR-MS offers a new analytical window to characterize starchy residue and its diagenetic products, and is able to recognize taxonomic signals with the potential to persist in fossil contexts. Introduction Materials and methods - Sample preparation and characterization - FTICR-MS analysis Results - Characterization of Maillard reaction products based on atomic ratios (H/C, O/C, N/C, N/O) and compound class distribution - Variations in molecular distribution Discussion - The Maillard reaction products - Preservation pathway - Diagenetic recalcitrance of Maillard reaction products Conclusions

Marine Oil Snow Sedimentation and Flocculent Accumulation (MOSSFA) can pose serious threats to the marine benthic ecosystem as it results in a deposition of oil contaminated marine snow on the sediment surface. In a microcosm experiment we investigated the effects of oil in combination with artificial marine snow or kaolin clay on two benthic invertebrate species and benthic meiofauna. The amphipod showed a dose-dependent decrease in survival for both oil-contaminated clay and oil-contaminated marine snow. The gastropod was only affected by the highest concentration of oil-contaminated marine snow and had internal concentrations of PAHs with a similar distribution as oil-contaminated marine snow. Benthic copepods showed higher survival in presence of marine snow. This study revealed that marine snow on the sediment after oil spills affects organisms in a trait-dependent way and that it can be a vector for introducing oil into the food web.

Sulfur incorporation into sedimentary organic matter has a key role in carbon preservation in the geosphere. Such processes can inform strategies for human timescale carbon storage to mitigate climate change impacts and thus more detailed knowledge of sulfur incorporation into biomass species is needed. Until recently, detailed chemical characterization of sulfurized organic matter was only possible by analyzing individual building blocks obtained after desulfurization reactions. In this study, Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS), with atmospheric pressure photoionization in positive ion mode, (+) APPI, was used to investigate the chemical composition of sulfur rich crude oils and to obtain mechanistic insights into the sulfur incorporation reactions happening during early diagenesis. Contrary to expectations, (+) APPI FTICR-MS data show that sulfurized lipids (with up to 6 sulfur atoms and up to m/z 1100) occur as free molecules in these oils, rather than within a macromolecular network linked by (poly)sulfide bridges. In contrast to the mature Peace River (Canada) oils, the thermally immature Rozel Point (USA) and Jianghan Basin (China) oils show a carbon number preference in sulfurized species resembling biogenic precursor molecules, which highlights the importance of S-bound molecules as geochemical proxies for early diagenetic processes. This study indicates that sulfur incorporation reactions involve the formation of S-cyclic structures in which the double bond equivalent is ≥ the number of S atoms. Collision induced dissociation (CID-) FTICR-MS experiments suggest the occurrence of intermolecular sulfur incorporation reactions, but only as a mechanism that is secondary to intramolecular sulfur addition. The CID-FTICR-MS experiments indicated that steroid sulfurization typically yields S-bearing cyclic structures and that thiol/thioether groups may be present throughout the chemical matrix but only to a minor extent. In addition, CID-FTICR-MS also confirms the occurrence of sulfurized alkenones in low maturity oils. Knowledge of organic sulfur molecule formation informs routes for carbon dioxide removal technologies that could be used to sequester carbon in the geosphere and/or hydrosphere in the form of recalcitrant organic species.

The conventional shake flask technique for determining oil-water partition ratios of benzene, toluene, ethylbenzene and xylene (BTEX) cannot accurately assess the extremes of high pressure and low water temperatures found in submarine oil spill conditions. An oil-water partitioning device has been constructed to experimentally simulate the partition behavior of BTEX compounds under submarine oil spill conditions, using simulated live oil (methane-charged), with saline waters over a range of pressure (2–15 MPa) and temperature (4–20 °C). Within the investigated ranges, the partition ratios of BTEX compounds increase proportionally with an increase in methane charging pressure (oil saturation pressure) and the degree of BTEX alkylation, and decrease with increase in temperature. The variation of the partition ratio values due to changes in system pressure and increasing oil methane concentration, is much more significant than those seen due to change in the temperature over the range studied. This data may be used in near-field and far-field distribution modeling of the environmental fate of highly toxic BTEX compounds, derived from submarine oil spills and their impact on the ecosystem. The parameters will also aid in the prediction of oil migration and dispersion away from the spill thus helping to improve response strategies.

The Deepwater Horizon oil spill released petroleum hydrocarbons that were depleted in δ13C and Δ14C at depth into the Gulf of Mexico. Stable-carbon and radiocarbon isotopic values and high-resolution mass spectrometry were used to follow the distributions of this petroleum and to track its transformation into petrocarbon, a term used to describe crude oil or transformed crude oil following biodegradation, weathering, oxygenation, or loss of lighter components. The term petrocarbon includes oil- or methane-derived carbon assimilated or incorporated into microbial biomass or into the food web as well as degraded and undegraded petroleum constituents. Here we report (1) the increase in the relative abundance of oxygen-containing carbon compounds making up the dissolved organic matter (DOM) with increasing depth through the water column, indicating the biodegradation of DOM as it was transported to depth in the water column, (2) the finding of 14C depletion in DOM indicating petrocarbon inputs, and (3) the decrease and subsequent increase of 14C in the isotopic composition of sinking particles indicating the capture of petrocarbon in sediment traps. In addition, we discuss the 14C depletion of this material once it is sedimented to the seafloor and the implications for oil spill budgets of seafloor petrocarbon deposition.

Marine Oil Snow Sedimentation and Flocculent Accumulation (MOSSFA) refers to the process of formation, sinking, and seafloor deposition of oil-contaminated marine snow and oil-mineral aggregates. MOSSFA was well documented in the northern Gulf of Mexico (GoM) in the aftermath of the Deepwater Horizon (DWH 2010) and likely occurred in the southern GoM during Ixtoc 1 (1979–1980). This chapter introduces Part IV: Oil Spill Records in Deep Sea Sediments and addresses a series of questions regarding MOSSFA in the sedimentary record:What were the characteristics of MOSSFA sedimentary inputs?What was the extent of MOSSFA on the seafloor?What postdepositional processes took place as a result of MOSSFA?Can MOSSFA be preserved in the sedimentary record?MOSSFA sedimentary inputs were comprised of three main components (biogenic, lithogenic, and petrogenic), many of which were surface derived. MOSSFA resulted in a four- to ten fold increase in bulk sediment accumulation rates, a two- to three fold increase in oil-derived hydrocarbon concentrations, a two- to three-order of magnitude increase in Corexit 9500A dispersant concentration, and two- to three fold increases in surface-derived biotic material (e.g., planktic foraminifera, diatoms). Estimates of the total spatial extent of MOSSFA on the seafloor of the northern GoM range from 1030 to 35,425 km2, accounting for between 3.7% and 14.4% of the total petroleum released during DWH. Increased microbial respiration of organic carbon caused depleted surface sediment oxygen, intensifying reducing conditions up to 3 years following DWH. Multiple proxies provided evidence of multi-year preservation of both oil residue in the sediments associated with DWH, MOSSFA, and the sedimentary event in the geologic record. Despite confounding factors in the southern GoM including regional events (e.g., volcanoes, hurricanes) and complex hydrocarbon backgrounds (e.g., natural seeps, oil, and gas infrastructure), multiple sedimentary proxies have provided evidence of degraded Ixtoc 1 oil-residue input and the MOSSFA sedimentary event preserved in the geologic record greater than 35 years after Ixtoc 1. Federal and international policies can be benefitted by incorporating MOSSFA with regard to response strategies, weighing the ecological trade-off between oiled coastlines and offshore benthic environments.

Geochemical studies can provide a record of environmental changes and biogeochemical processes in sedimentary systems. Analytical methods are in need of high-throughput procedures targeting recalcitrant and multiple chemical species for delineating ecological patterns and ecosystem health. The goal of this chapter is to summarize the analytical methods, recalcitrant molecules and transformed organic material used in previous studies as chemical indicators of the impact and fate of Deepwater Horizon (DWH) oil residues in sediments. Further monitoring of recalcitrant molecules and transformed material will help to elucidate the long-term fate of the DWH weathered oil in sedimentary environments of the Gulf of Mexico (GoM).

The oil spill from the Ixtoc 1 well in 1979 in the southern Gulf of Mexico (sGoM) was in many aspects very similar to the Deepwater Horizon (DWH) blowout offshore Louisiana 30 years later (2010), most importantly because of the subsurface nature of the oil release, the amount of oil released, and the extensive environmental distribution of the spilled oil, including coastal impacts. Because of that, the Ixtoc 1 spill can serve as an excellent analog to study and model the long-term oil weathering processes in coastal environments. In 2016, a research expedition sponsored by the Gulf of Mexico Research Initiative (GoMRI) visited many coastal sites in the sGoM, previously known to be impacted by the Ixtoc 1 spill, and collected oil residues. The residues were analyzed using targeted (GC-MS/MS) and non-targeted (FTICR-MS) approaches in order to assess their origin and the nature of weathering transformation products. The initial results suggest multi-decadal preservation potential of Ixtoc 1 spill residues in certain low-energy environments, such as coastal mangrove forests. These results provide valuable input for the modelling of long-term fate and impacts of the DWH spill.

During the past decade, Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) has been established as a technique of choice for the comprehensive chemical assessment of some of the most complex organic mixtures, such as petroleum, or dissolved organic matter. In the aftermath of the Deepwater Horizon (DWH) blowout, FTICR-MS demonstrated its applicability for the characterization of oil spill residues produced by abiotic weathering, such as photooxidation, and/or microbial processes and interactions, for example, marine oil snow aggregation. Such residues are abundant in high molecular weight, polar, and heteroatom-bearing chemical species, which cannot be analyzed by the typical oil spill forensics tools such as gas chromatography. Therefore, the expansion of the analytical window afforded by FTICR-MS is crucial for the monitoring and understanding of long-term oil spill fate. Furthermore, capability of FTICR-MS to characterize non-hydrocarbon petroleum fractions will be very important in the case of potential future spills of heavy, unconventional oils, such as bitumen.

The 2010 Deepwater Horizon blowout in the northern Gulf of Mexico (GoM) was the first major oil spill to impact the deep sea. This lack of precedent creates challenges for predicting the long-term fate of spilled oil constituents in the deep GoM. Depletion of oil residues in oxygenated seafloor sediments is thought to be relatively rapid, but as impacted horizons are buried by sediments and oxygen is depleted, biodegradation rates are likely to decrease. The sedimentary record of the 1979 Ixtoc 1 oil spill (southern GoM), the second largest marine oil spill to date, affords a window for forecasting the fate of constituents of spilled oil in the northern GoM over multi-decadal time scales.

The Deepwater Horizon (DWH) discharge is unique in that it represents the first large spill that occurred in the deep sea, and unparalleled volumes of chemical dispersant were applied during emergency response efforts. Thus, the DWH incident raised new challenges with regard to predictions of petroleum hydrocarbon (PHC) biodegradation and the fate of discharged hydrocarbons in the deep sea, which is permanently cold (~4 °C) and exposed to high hydrostatic pressure (1 MPa per 100 m). Although extensive information is available on the rates and controls of PHC biodegradation in marine environments, relatively few studies have been conducted under conditions resembling the deep sea. In particular, hydrostatic pressure is a key environmental parameter that has been largely overlooked in biodegradation studies, due to methodological challenges and the difficulty to obtain samples. Considering the rapid expansion of oil and gas drilling into deeper waters, there is an urgent need to improve understanding of the influence of low temperature and high pressure on biodegradation in order to better constrain the fate of hydrocarbons in the deep sea. This chapter addresses the current understanding of deep sea PHC biodegradation, highlighting discoveries made during the scientific response to the DWH disaster.

Petroleum is one of the most complex naturally occurring organic mixtures. The physical and chemical properties of petroleum in a reservoir depend on its molecular composition and the reservoir conditions (temperature, pressure). The composition of petroleum varies greatly, ranging from the simplest gas (methane), condensates, conventional crude oil to heavy oil and oil sands bitumen with complex molecules having molecular weights in excess of 1000 daltons (Da). The distribution of petroleum constituents in a reservoir largely depends on source facies (original organic material buried), age (evolution of organisms), depositional environment (dysoxic versus anoxic), maturity of the source rock (kerogen) at time of expulsion, primary/secondary migration, and in-reservoir alteration such as biodegradation, gas washing, water washing, segregation, and/or mixing from different oil charges. These geochemical aspects define the physical characteristics of a petroleum in the reservoir, including its density and viscosity. When the petroleum is released from the reservoir through an oil exploration accident like in the case of the Deepwater Horizon event, several processes are affecting the physical and chemical properties of the petroleum from the well head into the deep sea. A better understanding of these properties is crucial for the development of near-field oil spill models, oil droplet and gas bubble calculations, and partitioning behavior of oil components in the water. Section 3.1 introduces general aspects of the origin of petroleum, the impact of geochemical processes on the composition of a petroleum, and some molecular compositional and physicochemical background information of the Macondo well oil. Section 3.2 gives an overview over experimental determination of all relevant physicochemical properties of petroleum, especially of petroleum under reservoir conditions. Based on the phase equilibrium modeling using equations of state (EOS), a number of these properties can be predicted which is presented in Sect. 3.3 along with a comparison to experimental data obtained with methods described in Sect. 3.2.

Rationale A broad range of organic species in marine sediments is routinely used as biogeochemical proxies of Earth history. These species are typically analyzed using different analytical methods, targeting very specific components and often including time-intensive sample preparation. There is, therefore, a need for a more comprehensive, rapid and high-throughput approach to simultaneously analyze a broad range of known sedimentary polar species and also have a surveillance capability able to identify candidate new species classes. Methods Whole solvent extracts from recently deposited Gulf of Mexico marine sediments were obtained after a simple, one-step extraction. They were analyzed by Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS), using atmospheric pressure photoionization in positive ion mode (APPI-P), over a broad mass range (m/z 150–1500). Results From 3000 to over 5000 peaks per sample were assigned molecular formulae, and the majority of assignments (90%) showed an absolute error lower than 200 ppb. The detected species belong to the NO1–7, N4O2–8, O1–9, HC, N and OS compound classes, including known biomarker species such as pigments (e.g. tetrapyrrole macrocycles and carotenoids) and lipids (e.g. glycerol dialkyl glycerol tetraethers, GDGTs), but also compounds of still unknown detailed molecular structure, but with clear potential geochemical relevance. Conclusions The reported method enables rapid (12 min FTICR-MS analysis time) and simultaneous detection of a broad range of multi-heteroatom, polar organic species in whole sediment extracts. This allows for higher sample throughput, a more comprehensive investigation of sedimentary geochemistry, and potentially the discovery of new components and derivation of novel, multi-species proxies. Copyright © 2016 John Wiley & Sons, Ltd.

Oil industries generate large amount of oil wastewater worldwide and it is challenging to develop a sustainable technique to treat them due to the potential risk of contamination and recalcitrance. In this study, we employed microbial fuel cell to investigate biodegradation of crude oil with concomitant power generation. MnO2 coated anode was used to facilitate anoxic oil degradation due to better biofilm attachment, and fuel cell performance was compared with the uncoated carbon anode. Our study revealed that MFC with coated anode produced comparatively higher power density (47 mW m−2) than uncoated carbon anode (38 mW m−2), suggesting better removal of hydrocarbon components, also confirmed by oil-biodegradation studies (36% compared to 25.5% removal of total alkanes). The performance of the two cells was additionally evaluated by electrochemical, morphological, elemental and microbial community analysis. The prevalence of communities associated with hydrocarbon degradation and electrogenesis signify crude oil degradation with power generation.

In the aftermath of an oil spill, a possible response is the addition of chemical dispersants to prevent further spreading of the spilled oil on the ocean surface. The main objective is to enhance the formation of smaller oil droplets by reducing the interfacial tension between oil and water, thus dispersing the oil into the water column. The resulting solubilized oil with microdroplets along with the associated toxic compounds will be swiftly incorporated into the seawater. The formation of smaller oil droplets and the dispersant enhanced solubilized oil will increase its availability for bacteria and thus the biodegradability. Subsequently, the number and activity of oil-degrading bacteria increases, and more oil will be degraded in a shorter period of time (Kessler et al., Science 331:312–315, 2011). However, during the immediate release of the dispersed oil, volatile hydrocarbons including some of the more toxic compounds of benzene, toluene, ethylbenzene, and xylenes (BTEX) can inhibit the oil degradation (Sherry et al., Front Microbiol 5:131, 2014).Depending on the oceanic conditions, the addition of chemical dispersants can result in excessive formation of marine snow. It has been shown that the application of dispersants during phytoplankton blooms can trigger the formation of marine snow to which the sticky dispersed oil can bind. In the presence of mineral particles, oiled snow complexes are being formed that become negatively buoyant and sink to the ocean floor. As a result, oiled marine snow accumulates on the ocean floor where biodegradation is inhibited due to oxygen depletion.The abovementioned two mechanisms of inhibition of oil biodegradation upon application of oil spill dispersants will be discussed in this chapter.

In multispecies experiments performed in microcosms with natural sediment, it was investigated how the presence of marine snow affects the fate and ecological impact of deposited oil residues. The response of different taxonomic groups like nematodes, foraminifera, crustaceans and molluscs onto the presence of marine snow with or without oil was compared with the impact of deposited oil residues without marine snow. Also the effect of the presence of marine snow on oil biodegradation and transfer of oil-derived compounds to selected biota was studied. Although not designed to mimic the specific deep sea conditions in the Gulf of Mexico, the outcome of the experiments gave new insights in how a MOSSFA event can affect the benthic community. In general the experiments indicate that at field realistic oil-derived compound concentrations, the adverse impact of the marine snow on the sediment surface has a stronger impact on the benthic ecosystem than the oil’s toxicity on its own. In addition, the presence of marine snow reduces the degradation of the oil and can create an exposure route for animals that consume oiled marine snow and thus potentially enhances the ecological impact further.

Many of the molecular proxies commonly used for paleoenvironmental reconstruction are focused on a limited set of glycerol ether lipids, mainly due to the lack of more comprehensive analytical methods and instrumentation able to deal with a more diverse range of species. In this study, we describe an FTICR-MS-based method for rapid, nontargeted screening of ether lipid biomarkers in recent marine sediments. This method involves simplified sample preparation and enables rapid identification of known and novel ether lipid species. Using this method, we were able to identify complete series of core glycerol dialkyl glycerol tetraethers (GDGTs with 0 to 8 alicyclic rings), including the complete resolution of GDGT-4 and the unexpected detection of GDGTs with more than 5 rings, in sediments from mesophilic marine environments (sea surface temperature, SST, of 24-25 °C). Additionally, mono- and dihydroxy-GDGT analogs (including novel species with2 rings), as well as glycerol dialkanol diethers, GDDs (including novel species with5 rings) were detected. Finally, we putatively identified other, previously unreported groups of glycerol ether lipid species. Adequacy of the APPI-P FTICR-MS data for the determination of commonly used GDGT-based proxy indices was demonstrated. The results of this study show great potential for the use of FTICR-MS as both a rapid method for determining existing proxy indices and, perhaps more importantly, as a tool for the early detection of possible new biomarkers and proxies that may establish novel geochemical relationships between archaeal ether lipids and key environmental-, energy-, and climate-related system variables.

The dissolution of organic matter into water via oxidative processes, named oxycracking, has been practiced for a long time for the removal of organic pollutants, in which oxygen induces breakage and functionalization of organic molecules. Recently, oxycracking has been explored as an alternative approach to handling the increased amount of solid residues produced in oil sands upgrading activities that involve carbon rejection in solvent deasphalting units. This study uses an asphaltene-rich feedstock, operationally known as petroleum pitch, isolated from an Athabasca bitumen vacuum residue, which was submitted to oxycracking reactions at 200 and 220 °C. The feed and water-soluble fractions isolated at pH 1, termed acid-soluble oxidized asphaltenes (ASOA), were analyzed by ultrahigh-resolution mass spectrometry [Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS)] using electrospray and atmospheric pressure photoionization ion sources. FTICR-MS analysis revealed extensive oxidation of a...

After the Deepwater Horizon oil spill, a MOSSFA (Marine Oil Snow Sedimentation and Flocculent Accumulation) event took place, transporting an estimated 14% of total released oil to the sediment, and smothering parts of the benthic ecosystem. This microcosm study describes the effects of oiled artificial marine snow on benthic macroinvertebrates. Corophium volutator survival was reduced by 80% in oil-contaminated snow. Hydrobia ulvae survival was reduced by 40% in oil-contaminated snow, possibly due to consumption of oiled snow. Macoma balthica was sensitive to marine snow, addition of oil slightly decreased survival. This study reveals trait-dependent sensitivity to oil with or without marine snow. The main drivers for organismal response to marine snow and oil are motility, sensitivity to hypoxia and oil toxicity, and feeding habits. Adverse effects of MOSSFA events on benthos will have consequence for the benthic-pelagic habitat and food chain, and should receive more attention in oil spill management.

Canada’s oil sands region (COSR) is located in its western province of Alberta which contains one of the largest oil reserves in the world, in the form of biodegraded heavy oils and bitumens, but also has conventional oil containing reservoirs. In this chapter, we analyzed historical cases of oil releases related to oil production and transport in COSR, in order to determine long-term trends and the main causes of spills. Furthermore, we assessed the potential postspill environmental behavior, fate, and effects of nonhydrocarbon-rich COSR oil resources, in the context of their unique physicochemical properties. The long-term spill record shows a decreasing trend through time of released volumes relative to total oil output from COSR. Some of the largest oil releases occurred due to pipeline ruptures or leaks, often caused by corrosion. High oil viscosity and density reduce spill spreading, but can cause sinking of oil when spilled into water. The high concentrations of heteroatom-containing species in many COSR oils is a poorly understood risk factor affecting water solubility and environmental behavior in these polar compound-rich oil fractions. Advanced analytical tools and methods are needed to better understand the environmental impacts of spills of heteroatom-rich heavy oils and bitumens, and to improve spill response, monitoring, and remediation strategies.

Petroleum biomarkers such as hopanoids, steranes, and triaromatic steroids (TAS) are commonly used to investigate the source and fate of petroleum hydrocarbons in the environment based on the premise that these compounds are resistant to biotic and abiotic degradation. To test the validity of this premise in the context of the Deepwater Horizon disaster, we investigated changes to these biomarkers as induced by natural weathering of crude oil discharged from the Macondo Well (MW). For surface slicks collected from May to June in 2010, and other oiled samples collected on beaches in the northern Gulf of Mexico from July 2010 until August 2012, hopanoids with up to 31 carbons as well as steranes and diasteranes were not systematically affected by weathering processes. In contrast, TAS and C32- to C35-homohopanes were depleted in all samples relative to 17α(H),21β(H)-hopane (C30-hopane). Compared to MW oil, C35-homohopanes and TAS were depleted by 18 ± 10% and 36 ± 20%, respectively, in surface slicks collected from May to June 2010, and by 37 ± 9% and 67 ± 10%, respectively, in samples collected along beaches from April 2011 through August 2012. Based on patterns of relative losses of individual compounds, we hypothesize biodegradation and photooxidation as main degradation processes for homohopanes and TAS, respectively. This study highlights that (i) TAS and homohopanes can be degraded within several years following an oil spill, (ii) the use of homohopanes and TAS for oil spill forensics must account for degradation, and (iii) these compounds provide a window to parse biodegradation and photooxidation during advanced stages of oil weathering.

In situ burning is often used as a response method for oil slicks in the marine environment. This process however forms viscous tar-like residues that either float on the surface or sink through the water column, introducing organic species into the water phase. The interaction of this burn residue with the water phase also introduces dissolved organics into the water column. In this study, we conducted laboratory-scale experiments to characterize and compare the organic species entering the water phase from the petrogenic (fresh oil) and pyrogenic (burnt oil) input during oil spills. The oil and water-soluble organics were characterized using ultra-high-resolution mass spectrometry (FTICR-MS). The results show that burning strongly increases concentrations of oil-related constituents entering the water phase, due to transformation reactions producing oxidized organic species with higher water solubility. The pyrogenic water-soluble organics also showed a higher percentage of unsaturated compounds relative to the petrogenic fraction. The effect of these highly unsaturated and oxygenated organic species on oil spill fate and their ecosystem impacts is currently unknown.

Understanding weathering processes plays a critical role in oil spill forensics, which is based on the comparison of the distributions of selected compounds assumed to be recalcitrant and/or have consistent weathering transformations. Yet, these assumptions are based on limited laboratory and oil-spill studies. With access to additional sites that have been oiled by different types of oils and exposures, there is a great opportunity to expand on our knowledge about these transformations. Here, we demonstrate the effects of photooxidation on the overall composition of spilled oils caused by natural and simulated sunlight, and particularly on the often used polycyclic aromatic hydrocarbons (PAHs) and the biomarker triaromatic steranes (TAS). Both laboratory and field data from oil released from the Macondo well oil following the Deepwater Horizon disaster (2010), and heavy fuel-oil from the Prestige tanker spill (2002) have been obtained to improve the data interpretation of the typical fingerprinting methodology.

Multivariate curve resolution-alternating least squares (MCR-ALS) analysis is proposed to solve chromatographic challenges during two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS) analysis of complex samples, such as crude oil extract. In view of the fact that the MCR-ALS method is based on the fulfillment of the bilinear model assumption, three-way and four-way GC × GC-TOFMS data are preferably arranged in a column-wise superaugmented data matrix in which mass-to-charge ratios (m/z) are in its columns and the elution times in the second and first chromatographic columns are in its rows. Since m/z values are common for all measured spectra in all second-column modulations, unavoidable chromatographic challenges such as retention time shifts within and between GC × GC-TOFMS experiments are properly handled. In addition, baseline/background contributions can be modeled by adding extra components to the MCR-ALS model. Another outstanding aspect of MCR-ALS analysis is its extreme flexibility to consider all samples (standards, unknowns, and replicates) in a single superaugmented data matrix, allowing joint analysis. In this way, resolution, identification, and quantification results can be simultaneously obtained in a very fast and reliable way. The potential of MCR-ALS analysis is demonstrated in GC × GC-TOFMS analysis of a North Sea crude oil extract sample with relative errors in estimated concentrations of target compounds below 6.0 % and relative standard deviations lower than 7.0 %. The results obtained, along with reasonable values for the lack of fit of the MCR-ALS model and high values of the reversed match factor in mass spectra similarity searches, confirm the reliability of the proposed strategy for GC × GC-TOFMS data analysis.

Pesticide determination by gas chromatography (GC) and supercritical fluid chromatography (SFC) techniques has been presented in this article. Instrumentation used in the different pesticide class analyses, such as injection (vaporizing, cold injection and large volume) and detection techniques (nitrogen–phosphorus detection, NPD; flame photometric detection, FPD; electron capture detection, ECD), and hyphenated systems (atomic emission detection, AED; mass spectrometry, MS; Fourier transform infrared, FTIR) used in GC and SFC determination of pesticides are presented. The figures of merit of each detection technique are outlined. Instrumental set-ups which combine extraction and separation techniques are also presented. Stationary phases used in GC and the type of SFC columns used in the determination of pesticides are also reported. Finally, the application of recent GC developments in the determination of pesticides is mentioned.

An effect-directed analysis (EDA) of fresh and artificially weathered (evaporated, photooxidized) samples of North Sea crude oil and residual heavy fuel oil is presented. Aliphatic, aromatic, and polar oil fractions were tested for the presence of aryl hydrocarbon receptor (AhR) agonist and androgen receptor (AR) antagonist, demonstrating for the first time the AR antagonist effects in the aromatic and, to a lesser extent, polar fractions. An extension of the typical EDA strategy to include an N-way partial least-squares (N-PLS) model capable of relating the comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC × GC–TOFMS) data set to the bioassay data obtained from normal-phase LC fractions is proposed. The predicted AhR binding effects in the fresh and artificially weathered aromatic oil fractions facilitated the identification of alkyl-substituted three- and four-ring aromatic systems in the active fractions through the weighting of their contributions to the observed effects. A N-PLS chemometric model is demonstrated as a potentially useful strategy for future EDA studies that can streamline the compound identification process and provide additional reduction of samples’ complexity. The AhR binding effects of the suspected compounds predicted by N-PLS and identified by GC × GC–TOFMS were confirmed using quantitative structure–activity relationship (QSAR) estimates.

7 páginas, 5 tablas, 1 figura, Artificial weathering of Angolan crude and a Heavy Fuel Oil (HFO) was performed by evaporation and photooxidation. The aliphatic, aromatic, polar and asphaltene fractions of the fresh and weathered oils were isolated. The toxicity of the water accommodated fraction or an oil/fraction dissolved in DMSO was assessed using the sea urchin embryo test. Photooxidation was observed to decrease the aromatics content and increase polar compounds. A slight reduction in the toxicity of Angolan crude was observed following weathering for the water-accommodated fraction and the extract in DMSO, but no effect was seen for the Heavy Fuel Oil. For aliphatic compounds, the toxicity decreased in the order fresh > evaporated > photooxidated for both Angolan crude and HFO. Weathering slightly increased the toxicity of the aromatic and polar fractions of the oil. The aromatic fractions were responsible for most of the toxicity and the polar compounds were the second most important toxic components, despite having less or similar abundance than the aliphatic fraction. The toxic contribution of the aromatic compounds was higher for the HFO than for the Angolan crude. A decrease in the toxicity of Angolan crude following weathering correlated with a reduction in the toxicity of the aliphatic fraction., J.M.B. acknowledges financial support by MICINN (projects Ref. CTM2008-02718-E/MAR and CTM2008-02721-E/MAR), K.V.T. by Research Council of Norway (Projects 189613 and 18961a), R.B. by MICINN (Projects Ref. CTM2009-10908 and ERAC-CT2005-016165) through the project “European concerted action to foster prevention and best response to accidental marine pollution – AMPERA” (ERAC-CT2005-016165) within the framework of the EU ERA-Net Initiative (6th Framework Program).

Oil spills relating to shipping incidents remain of substantial concern with respect to marine pollution. Whilst most frequently a reactive approach is adopted in post-incident monitoring (for the specific product involved), this paper reports important physical and compositional characteristics of commonly transported oils and oil products to afford pro-active assessments. These properties include specific gravity, viscosity, elemental composition and, of particular relevance, the relative class compositions between aliphatics, aromatics, resins and asphaltenes. The latter were determined experimentally using thin layer chromatography with flame ionization detection. Diagnostic ratios of specific compounds are reported, statistically analysed, and their significance in identification of different oil types and the weathering processes is discussed. The influence of the properties on fates under different environmental conditions (selected to represent contrasting European regional seas) are examined using the NOAA Automated Data Inquiry for Oil Spills (ADIOS2) model. Relative contributions of the different environmental conditions and properties to the fate of the oil at sea are discussed., Financial support was obtained from the MCINN, Spain (CTM2008-02718-E/MAR and -02721-E/MAR) and Defra, UK (Project Ref. ME1312) through the project ‘‘European concerted action to foster prevention and best response to accidental marine pollution – AMPERA’’ (ERAC-CT2005-016165) within the framework of the EU ERA-Net Initiative (6th Framework Program). J.R.R. kindly acknowledges a pre-doctoral fellowship (JAE Predoc) from the Spanish National Council of Research (CSIC) and European Social Fund (ESF). Dr Luis Carlos Quintero Toscano is greatly acknowledged for providing oil assays data. Dr D. Calderon-Preciado is acknowledged for her help with the statistical analyses, Dr N. Jimenez for GC-MS of oil samples and Mrs Altamira Arcos for technical assistance in TLC-FID analyses.

Oil and chemical spills in the marine environment are an issue of growing concern. Oil exploration and exploitation is moving from the continental shelf to deeper waters, and to northern latitudes where the risk of an oil spill is potentially greater and may affect pristine ecosystems. Moreover, a growing number of chemical products are transported by sea and maritime incidents of hazardous and noxious substances (HNS) are expected to increase. Consequently, it seems timely to review all of the experience gained from past spills to be able to cope with appropriate response and mitigation strategies to combat future incidents. Accordingly, this overview is focused on the dissemination of the most successful approaches to both detect and assess accidental releases using chemical as well as biological approaches for spills of either oil or HNS in the marine environment. Aerial surveillance, sampling techniques for water, suspended particles, sediments and biota are reviewed. Early warning bioassays and biomarkers to assess spills are also presented. Finally, research needs and gaps in knowledge are discussed.

Comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOFMS) combined to multivariate curve resolution-alternating least-squares (MCR-ALS) is proposed for the resolution and quantification of very complex mixtures of compounds such as polycyclic aromatic hydrocarbons (PAHs) in heavy fuel oil (HFO). Different GC × GC-TOFMS data slices acquired during the analysis of HFO samples and PAH standards were simultaneously analyzed using the MCR-ALS method to resolve the pure component elution profiles in the two chromatographic dimensions as well as their pure mass spectra. Outstandingly, retention time shifts within and between GC × GC runs were not affecting the results obtained using the proposed strategy and proper resolution of strongly coeluted compounds, baseline and background contributions was achieved. Calibration curves built up with standard samples of PAHs allowed the quantification of ten of them in HFO aromatic fractions. Relative errors in their estimated concentrations were in all cases below 6%. The obtained results were compared to those obtained by commercial software provided with GC × GC-TOFMS instruments and to Parallel Factor Analysis (PARAFAC). Inspection of these results showed improvement in terms of data fitting, elution process description, concentration relative errors and relative standard deviations., Financial support was obtained from MCINN (Projects ref. . CTQ2009-11572, CTM2008-02718-E, RAMOCS, and CTM2008-02721-E/MAR, TOXPROF) and the project “European concerted action to foster prevention and best response to accidental marine pollution-AMPERA” (ERAC-CT2005-016165) within the framework of the EU ERA-Net Initiative (sixth Framework Program). J.R.R. kindly acknowledges a predoctoral fellowship (JAE Predoc) from the Spanish National Council of Research (CSIC).

A drainage channel network in Vojvodina, Serbia, made for collection and transition of (sub)surface waters from waterlogged arable land areas, is exposed to diffuse and/or point contamination sources. Over time, the channel network has accumulated sediment material containing potentially harmful organic substances such as polycyclic aromatic hydrocarbons (PAHs). In this study, the concentration of 16 environmentally relevant PAH substances from 42 sampling points in drainage channel sediments was analysed. Excessive (>10 mg/kg) total concentration of PAHs, i.e. potentially harmful from the ecological perspective, was detected in 24% of analysed channel sediment samples, with 17% of samples containing 10-40 mg PAHs/kg, and 7% more than 40 mg PAHs/kg. At specific channel locations, increased concentrations (>13 mg/kg) of certain carcinogenic PAHs were also confirmed, representing up to 95% of total PAHs concentration. Assessment of PAHs sources suggests their predominantly pyrolitic and mixed origin. One of the main sources of increased PAH concentrations in analysed sediments can be attributed to combustion and direct discharging of different untreated effluents and wastewaters from industrial facilities and/or municipal areas.