Pyrolysis of asphaltenes and biomarkers for the fingerprinting of the Amoco-Cadiz oil spill after 23 years

Recognizing and compensating for interference from the sediment’s background organic matter and biodegradation during interpretation of biomarker data from seafloor hydrocarbon seeps: An example from the Marco Polo area seeps, Gulf of Mexico, USA

“…9B). These differences in the pyrolysate's steranes are consistent with the results from similar experiments with crude oil asphaltene reported by Dembicki and Mathiesen (1994), Holba et al (2005), and Oudot and Chaillan (2009). This may suggest that there is some discrimination against the diasteranes, and perhaps some of the regular steranes stereochemistries, in the occlusion into the asphaltene aggregates.…”

Salt Marsh Bacterial Communities before and after the Deepwater Horizon Oil Spill

“…Although a cascading series of long-term biogeochemical consequences, due to the microbial response, was anticipated for the marsh ecosystem (41), some of the earlier studies suggested a faster-than-expected recovery (16,42). This assessment was likely premature because high concentrations of weathered oil and oil residues, trapped by salt marsh vegetation, lingered for more than a year after the spill and were expected to persist under anoxic conditions for potentially decades (43)(44)(45)(46). Therefore, the long-term effect of the spill on marsh microbial communities, and the implications for coastal ecosystems overall, still remain unclear because long-term studies of marsh microbial communities have been needed (47,48).…”

“…Moreover, half of the marshes had n-alkane biomarkers denoting oil contamination, despite the lower concentrations due to the effects of abiotic weathering and biodegradation over time (44). Most of the earlier DWH studies did not consider how the heterogeneous, weathered oil residues could linger in marsh sediments for years (32,43) or become redistributed by storms years after the main oiling. We detected oil up to 100 m into the marshes by late 2011 (46), which contradicted earlier studies that claimed oil was restricted to shoreline edges (42,58).…”

Post-incident monitoring to evaluate environmental damage from shipping incidents: Chemical and biological assessments

“…This can facilitate identification of weathered spill samples. In other research (Oudot and Chaillan, 2010), asphaltene fractions from heavily weathered oil spill residues were used in order to reconstruct a GC profile of the original fuel, and successfully identify the sources. However, in all the cases, the limited resolution power of conventional GC is an intrinsic problem and restricts the power of the fingerprinting technique.…”