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Steven J Rowland - One of the best experts on this subject based on the ideXlab platform.
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chemical and toxicological characterization of an Unresolved Complex Mixture rich biodegraded crude oil
Environmental Toxicology and Chemistry, 2009Co-Authors: Alf G Melbye, Steven J Rowland, Odd Gunnar Brakstad, Jorunn Nerbo Hokstad, Inger Katharina Gregersen, Bjorn Henrik Hansen, Andy M Booth, Knut E TollefsenAbstract:Chemical and toxicological characterization of Unresolved Complex Mixtures in the water-soluble fraction of an artificially weathered Norwegian Sea crude oil was determined by a combination of chemical analysis and toxicity testing in fish in vitro bioassays. The water-soluble fraction of the crude oil was separated into 14 increasingly polar fractions by preparative high-pressure liquid chromatography. The in vitro toxicity (7-ethoxyresorufin
toxicity was one of the most polar fractions, accounting gravimetrically for more than 70% of the organic material in the water-soluble fraction and dominated by an Unresolved Complex Mixture. Chemical analysis by gas chromatography-mass spectrometry and comprehensive two-dimensional gas chromatography—time of flight—mass spectrometry identified a large number of cyclic and aromatic sulfoxide compounds and low amounts of benzothiophenes (<0.1% of total mass) in this fraction. Commonly monitored toxic components of crude oil (e.g., naphthalenes, polycyclic aromatic hydrocarbons, and alkylated phenols) eluted in less polar fractions, characterized by somewhat lower toxicity. Normalization of in vitro responses to the mass in each fraction demonstrated a more even distribution of toxicity, indicating that toxicity in the individual fractions was related to the amount of material present. Although polar and nonpolar compounds contribute additively to crude oil toxicity, the water-soluble fraction was dominated by polar compounds because of their high aqueous solubility and the high oil—water loading. Under these conditions, the polar Unresolved Complex Mixture—rich fraction might account for a large portion of crude oil toxicity because of its high abundance in the water-soluble fraction. -
CHEMICAL AND TOXICOLOGICAL CHARACTERIZATION OF AN Unresolved Complex Mixture-RICH BIODEGRADED CRUDE OIL
Environmental Toxicology and Chemistry, 2009Co-Authors: Alf G Melbye, Steven J Rowland, Odd Gunnar Brakstad, Jorunn Nerbo Hokstad, Inger Katharina Gregersen, Bjorn Henrik Hansen, Andy M Booth, Knut E TollefsenAbstract:Chemical and toxicological characterization of Unresolved Complex Mixtures in the water-soluble fraction of an artificially weathered Norwegian Sea crude oil was determined by a combination of chemical analysis and toxicity testing in fish in vitro bioassays. The water-soluble fraction of the crude oil was separated into 14 increasingly polar fractions by preparative high-pressure liquid chromatography. The in vitro toxicity (7-ethoxyresorufin
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Can Amphipod Behavior Help to Predict Chronic Toxicity of Sediments
Human and Ecological Risk Assessment, 2007Co-Authors: Alan G. Scarlett, Steven J Rowland, Martin N. Canty, Emma Smith, Tamara S. GallowayAbstract:ABSTRACT Amphipods are widely used in both acute and chronic (sub-lethal) sediment tests. Acute sediment tests provide relatively rapid results, but may fail to detect moderately toxic contaminants that are bound to the sediment, whereas chronic life-cycle tests are rarely performed as they are time consuming and expensive. Observations during chronic testing of oil-contaminated sediment suggested that there may be a link between the behavior of the marine amphipod Corophium volutator and reduction in growth rate. Behavior tests were performed with six individual amphipods per treatment using sediment spiked with weathered Forties oil with burrowing time, re-emergence from sediment, and activity prior to burrowing as endpoints. Further behavior tests were used to predict the chronic toxicity of sediments spiked with three crude oils each with a dominant Unresolved Complex Mixture of hydrocarbons (UCM). The effect of sediment type on behavior was also investigated. The results suggested that although the b...
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isolation of individual hydrocarbons from the Unresolved Complex hydrocarbon Mixture of a biodegraded crude oil using preparative capillary gas chromatography
Organic Geochemistry, 2005Co-Authors: Paul A Sutton, C A Lewis, Steven J RowlandAbstract:Abstract We describe the isolation, using preparative capillary gas chromatography, of hydrocarbon fractions from an Unresolved Complex Mixture (UCM) of hydrocarbons isolated from a biodegraded crude oil. Some of the individual hydrocarbons in these fractions were then resolved by gas chromatography (GC) and identified using GC–mass spectrometry (GC–MS). The mass spectra contained distinct molecular ions. As a preliminary example, after preparative open column chromatography, preparative HPLC (three columns in series) and preparative GC on two stationary phases, one of the compounds from the UCM was tentatively identified using electron impact ionisation GC–MS as a novel C26 17-desmethyl triaromatic steroid. If the concentration of this compound (ca. 4 μg g−1 whole oil) is typical of other individual compounds in the UCM, the proportion of UCM represented by each compound is obviously very small (
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Toxic effects of Unresolved Complex Mixtures of aromatic hydrocarbons accumulated by mussels, Mytilus edulis, from contaminated field sites.
Environmental Science & Technology, 2003Co-Authors: Peter Donkin, Emma Smith, Steven J RowlandAbstract:: Exposure of marine mussels (Mytilus edulis) to an Unresolved Complex Mixture (UCM) of aromatic hydrocarbons isolated from a crude oil has been shown to reduce their feeding rate by 40%. The present study was undertaken to determine whether UCMs bioaccumulated by mussels in the field are also toxic. The feeding rate of mussels derived from polluted sites increased when they were placed in clean water, pointing to a loss of toxic agents from the tissues. At the end of the depuration period, water in which mussels from an oil-polluted site had been held contained a UCM. Steam-distillation extracts of the tissues of mussels taken from several polluted sites were shown to be highly toxic to the feeding activity of juvenile mussels. The tissues of mussels from these sites contained UCMs. Nontoxic steam distillates from clean mussels did not. Steam-distillation extracts of mussels from an oil-polluted site were fractionated by normal-phase high-performance liquid chromatography. A fraction, largely comprising a "monoaromatic" UCM, reduced the feeding rate of juvenile mussels by 70%. Two later-eluting fractions containing aromatic UCMs also produced smaller depressions in feeding rate. These results support our contention that some aromatic UCM hydrocarbons constitute a forgotten pollutant burden in the marine environment.
Bernd R T Simoneit - One of the best experts on this subject based on the ideXlab platform.
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Lipid Biomarker Analysis of Suspended Particulate Matter from the Great Kwa River, SE Nigeria: Origins and Environmental Implications of Biogenic and Anthropogenic Organic Compounds
Aquatic Geochemistry, 2017Co-Authors: Bernd R T Simoneit, Oliva Pisani, Bassey O. Ekpo, Ebirien P. Fubara, Okon D. EkpaAbstract:Biomarkers found in natural waters, sediments, soils, fossils, crude oil, and coal can be unambiguously linked to specific precursors biosynthesized by biota. Petroleum and its refinery products carry their biomarker information into the environment when they are released by pollution. Lipid biomarkers can be used to assess the environmental status of an ecosystem and the degree to which it has been influenced by biogenic and anthropogenic inputs. The marine ecosystem of the southeastern Niger Delta of Nigeria is receiving new attention due to increased human and industrial development and the consequent potential health effects. Suspended particulate matter (SPM) from the Great Kwa River was characterized using biomarkers to assess such pollution. The total organic carbon contents of SPM from the river at low and high tide was 12–50% (avg 34.75%) and 16–28% (avg 24.25%), respectively. The lipid biomarkers identified using gas chromatography–mass spectrometry were mainly n -alkanes, n -alkan-2-ones, triterpenoids and minor amounts of aromatic compounds. The n -alkanes ranged from C _17 to C _35, with an odd/even predominance and C _max > 27, indicating a mixed origin from higher plant wax, biodegraded detritus, and petroleum. The n -alkan-2-ones in most samples ranged from C _16 to C _33, with C _max = 31, also supporting an input from vascular plants dominating the riparian zone along the river. The triterpenoids, mainly taraxerone, taraxerol, α- and β-amyrins, and friedelin, also derived from higher plants (angiosperms). Minor amounts of aromatic hydrocarbon derivatives from α- and β-amyrins were present and are likely the result of different diagenetic processes. The presence of trace fossil fuel-derived hopanes with an Unresolved Complex Mixture of branched and cyclic hydrocarbons supported a minor petroleum product input to the SPM of the Great Kwa River.
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Characterization and sources of extractable organic matter from sediment cores of an urban lake (Tasik Perdana), Kuala Lumpur, Malaysia
Environmental Earth Sciences, 2014Co-Authors: Aliaa Diyana Azizuddin, Mhd Radzi Bin Abas, Bernd R T SimoneitAbstract:The extractable organic matter of sediment samples from six sampling sites in Lake Perdana, Kuala Lumpur, was analyzed to characterize the source inputs. The analysis of aliphatic homologous series indicated that terrestrial higher plant waxes can be assigned as the major sources of the identified aliphatic components in the lake sediments. The presence of an Unresolved Complex Mixture of branched and cyclic compounds and a series of hopanes ranging from C_27 to C_35 reflected the contamination by petroleum residues from urban vehicular emissions brought in by runoff and fallout. The steroids present included stenols and stanols and showed an input of organic matter from higher plants. The detected pentacyclic triterpenoids comprised oleanane, ursane, lupane and friedelane skeletons including unsaturated oxygenated, mono-, di- and triaromatic counterparts. They are recognized as biomarkers for angiosperms. The presence of des-A-triterpenoids and their aromatized derivatives as the major diagenetic products of triterpenoids reflected the degradation of natural organic matter in the sediments occurring under mainly anoxic conditions. In addition, the presence of tetrahymanol and ββ-bishomohopan-32-ol indicated a minor algal/plankton and bacterial input to the sediments.
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Organic tracers in sediments from the coastal zone of Ras Abu el-Darag, Gulf of Suez
Environmental Geology, 2009Co-Authors: Ahmed I. Rushdi, Tarek A. T. A. Kassim, Bernd R T SimoneitAbstract:Sediment samples from the coastal zone of the Gulf of Suez contain a variety of organic compounds from anthropogenic and natural sources. A total of 12 surface samples of bottom sediments were collected with an Ekman grab sampler along an off-shore transect south of Ras Abu el-Darag. The samples were extracted with a Mixture of dichloromethane and methanol (3:1 v/v) after drying and sieving through 250 μm mesh. The extracts were derivatized and analyzed by gas chromatography–mass spectrometry in order to characterize the chemical composition and sources of the organic components. Marine with minor terrestrial biota were the major natural sources of organic tracers and included n -alkanoic acids, sterols and saccharides (5.7–76.7%). Anthropogenic sources, from petroleum related activities, detergent usage for spill cleaning and littering, are indicated by the presence of n -alkanes with carbon preference index ≤1.0, hopanes, steranes, Unresolved Complex Mixture of branched and cyclic hydrocarbons, alkyl nitriles, alkamides and plasticizers. Their total relative concentrations ranged from 23.3 to 97.3% of the total extracts. Petroleum residues from natural seepage may also be part of these hydrocarbons. The levels of anthropogenic inputs decrease from about 94% in coastal zone sediments to about 20% in sediments from the reef front.
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Levels and distributions of organic source tracers in air and roadside dust particles of Kuala Lumpur, Malaysia
Environmental Geology, 2007Co-Authors: Nasr Yousef M. J. Omar, M. Radzi Bin Abas, Noorsaadah A. Rahman, Norhayati Mohd. Tahir, Ahmed I. Rushdi, Bernd R T SimoneitAbstract:The concentrations of n -alkanes, Unresolved Complex Mixture (UCM), petroleum molecular markers, other tracers of cooking and burning emissions, and natural background in atmospheric particles and roadside dust particles were measured at eight locations in the city center and the suburbs of Kuala Lumpur, Malaysia. Atmospheric particles were collected using high-volume filtration (PM-10, GFF) over 24 h average periods. Road dusts were swept up, dried and sieved. Both types of samples were extracted with dichloromethane/methanol Mixture (3:1 v/v) by ultrasonic agitation. The extracts were then fractionated by column chromatography and the alkanes subjected to gas chromatography–mass spectrometry (GC–MS). Total extracts were also analyzed directly by GC–MS after silylation. The molecular distributions of compounds as well as diagnostic geochemical ratios were determined in order to identify the sources of the organic compounds. Samples collected from a rural area and lubricating oils were also analyzed for comparisons. Anthropogenic and biogenic sources such as vehicular emissions, waxes of higher plants, food cooking operations, and biomass and domestic refuse burning processes contributed to the organic matter content of atmospheric and to lesser extent, roadside dust particles.
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The extent and significance of petroleum hydrocarbon contamination in Crater Lake, Oregon
Hydrobiologia, 2007Co-Authors: Daniel R. Oros, Robert W. Collier, Bernd R T SimoneitAbstract:In order to evaluate hydrocarbon inputs to Crater Lake from anthropogenic and natural sources, samples of water, aerosol, surface slick and sediment were collected and analyzed by gas chromatography-mass spectrometry (GC-MS) for determination of their aliphatic and aromatic hydrocarbon concentrations and compositions. Results show that hydrocarbons originate from both natural (terrestrial plant waxes and algae) and anthropogenic (petroleum use) sources and are entering the lake through direct input and atmospheric transport. The concentrations of petroleum hydrocarbons range from low to undetectable. The distributions and abundances of n -alkanes, polycyclic aromatic hydrocarbons (PAH) and Unresolved Complex Mixture (UCM) from petroleum are similar for all surface slick sampling sites. The estimated levels of PAH in surface slicks range from 7–9 ng/m^2 which are low. Transport of petroleum-derived hydrocarbons from the lake surface has resulted in their presence in some sediments, particularly near the boat operations mooring (total petroleum HC = 1440 µg/kg, dry wt. compared to naturally derived n -alkanes, 240 µg/kg, dry wt.). The presence of biomarkers such as the tricyclic terpanes, hopanes and steranes in shallow sediments further confirms petroleum input from boat traffic. In the deep lake sediments, petroleum hydrocarbon concentrations were very low (16 µg/kg, dry wt.). Very low concentrations of PAH were detected in shallow sediments (17–40 µg/kg at 5 m depth near the boat operations) and deep sediments (3–15 µg/kg at 580 m depth). The individual PAH concentrations in sediments (µg/kg or ppb range) are at least three orders of magnitude less than reported threshold effects levels (mg/kg or ppm range, test amphipod Hyalella azteca ). Therefore, no adverse effects are expected to occur in benthic biota exposed to these sediments. Boating activities are leaving a detectable level of petroleum in surface waters and lake sediments but these concentrations are very low .
S Schouten - One of the best experts on this subject based on the ideXlab platform.
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sulfurization of carbohydrates results in a sulfur rich Unresolved Complex Mixture in kerogen pyrolysates
Energy & Fuels, 2003Co-Authors: J Sinninghe S Damste, B E Van Dongen, S SchoutenAbstract:Pyrolysates of the organic carbon-rich and oil-prone rocks of the Kimmeridge Clay Formation (KCF) are dominated by a sulfur-rich Unresolved Complex Mixture (UCM). Structural characterization of this UCM by preparative capillary gas chromatography, gas chromatography (GC), gas chromatography/mass spectrometry (GC/MS), isotope-ratio-monitoring GC/MS, elemental analysis, nuclear magnetic resonance spectroscopy, and Fourier transform infrared absorption, as well as chemical degradation by desulfurization and ruthenium tetroxide treatment, revealed that this UCM probably consists of a large number of sulfur-bound and oxygen-bound, short-chain carbon skeletons. These skeletons are part of oligomeric structures of diverse molecular weight that elute during GC analysis as an UCM. These skeletons most likely originate from carbohydrates that have been incorporated into macromolecular organic matter through sulfurization during early diagenesis. Upon pyrolysis, this macromolecular material is transferred into the oligomeric structures present in the UCM. Sulfur-rich UCMs have also been identified in several other kerogens, suggesting that carbohydrate sulfurization could be an important mechanism for the preservation of sedimentary organic carbon. In addition, it is likely that the sulfurized carbohydrates form a substantial part of sulfur-rich kerogens and that these thermally labile structures cause the early generation of petroleum from sulfur-rich kerogens.
Marcelo R. Alexandre - One of the best experts on this subject based on the ideXlab platform.
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Distribution and sources of aliphatic hydrocarbons in surface sediments of Sergipe River estuarine system
Marine Pollution Bulletin, 2012Co-Authors: Manoel B. Lima, Elaine A. Feitosa, Elissandro S. Emídio, Haroldo S. Dórea, Marcelo R. AlexandreAbstract:Abstract The assessment of aliphatic hydrocarbons was performed in the Sergipe River estuarine system, northeastern Brazil. Aliphatic hydrocarbons concentration ranged from 9.9 ug g −1 up to 30.8 ug g −1 of dry sediment. The carbon preference index (CPI, based on n C 24 to n C 34 range), indicated predominance of petrogenic input in two of the sites analyzed (P4 and P5). The Unresolved Complex Mixture (UCM) was found to be present in seven of the nine sites sampled (except for P4 and P5). Overall, the results of this work suggest that there is a mix of organic matter sources to the sediment. Although the coast of Sergipe has an intense off shore petroleum exploration and the Sergipe River crosses the entire city of Aracaju, the capital city of Sergipe, non-significant anthropogenic fingerprint was assessed.
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Distribution and sources of aliphatic hydrocarbons in surface sediments of Sergipe River estuarine system
Marine Pollution Bulletin, 2012Co-Authors: Manoel B. Lima, Elaine A. Feitosa, Elissandro S. Emídio, Haroldo S. Dórea, Marcelo R. AlexandreAbstract:The assessment of aliphatic hydrocarbons was performed in the Sergipe River estuarine system, northeastern Brazil. Aliphatic hydrocarbons concentration ranged from 9.9ugg -1 up to 30.8ugg -1 of dry sediment. The carbon preference index (CPI, based on nC 24 to nC 34 range), indicated predominance of petrogenic input in two of the sites analyzed (P4 and P5). The Unresolved Complex Mixture (UCM) was found to be present in seven of the nine sites sampled (except for P4 and P5). Overall, the results of this work suggest that there is a mix of organic matter sources to the sediment. Although the coast of Sergipe has an intense off shore petroleum exploration and the Sergipe River crosses the entire city of Aracaju, the capital city of Sergipe, non-significant anthropogenic fingerprint was assessed. © 2012 Elsevier Ltd.
Constantine Stalikas - One of the best experts on this subject based on the ideXlab platform.
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Recent Environmental Changes in the Shallow Lake Pamvotis (NW Greece): Evidence from Sedimentary Organic Matter, Hydrocarbons, and Stable Isotopes
Archives of Environmental Contamination and Toxicology, 2009Co-Authors: Victoria Daskalou, Polona Vreča, Gregor Muri, Constantine StalikasAbstract:Lake Pamvotis is a shallow Mediterranean lake located in northwestern Greece that has been recognized as an internationally important conservation site. Here, an unprecedented investigation was undertaken to obtain and evaluate data related to sedimentary organic matter, hydrocarbon content, and stable isotopes of Lake Pamvotis sediments, thus tracking the origin of organic inputs and providing a record of environmental status. The study revealed a distinct spatial distribution of polycyclic aromatic hydrocarbons (PAHs) with values between 34.7 and 1600 μg/kg and a rather uniform pattern for n -alkanes with concentrations falling below 41.4 μg/g. A significant contribution of an Unresolved Complex Mixture indicated anthropogenic petroleum contamination. Further study of relevant indexes and geochemical biomarkers supported a mixed-source input of aliphatic hydrocarbons. With regard to PAHs, there was strong evidence that their dominant origin is pyrogenic. Finally, considerable excursion in δ^13C_org was attributed to changes in dissolved inorganic carbon accompanied by increased input of effluents and recycling of organic carbon within the lake, whereas the rise in isotopic composition of nitrogen was associated with agricultural runoff and sewage input from the town of Ioannina.
