title: Oxygenated weathering products of Deepwater Horizon oil come from surprising precursors.
abstract: Following the release of crude oil from the Macondo well in 2010, a wide range of weathering processes acted on the spilled oil. A recent study revealed that samples from this spill were oxidized into oxygenated hydrocarbons (OxHC) comprising more than 50% of the extracted hydrocarbons. The precursors of these compounds were not identified despite using a wide range of analytical tools, including gas chromatography (GC). To search for these precursors, over 40 samples were analyzed by comprehensive two-dimensional gas chromatography (GC×GC), one of the largest studies of its kind to date. Partial least squares regression was employed to elucidate the GC×GC peaks that could be the precursors of OxHC in our samples. We found that the formation of OxHC correlated with the disappearance of saturated hydrocarbons, including alkylcyclopentanes, alkyl cyclohexanes, alkylated bicyclic saturated compounds, tricyclic terpanpoids, and alkylbenzenes. These results indicate a previously under-reported chemodynamic process in oil spill weathering.
authors.affiliation: Department of Science, United States Coast Guard Academy, New London, CT, USA. Electronic address: gregory.hall@uscga.edu.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Hall
authors.affiliation: Department of Science, United States Coast Guard Academy, New London, CT, USA.
authors.forename: Glenn S
authors.initials: GS
authors.lastname: Frysinger
authors.affiliation: Woods Hole Oceanographic Institution, Department of Marine Chemistry and Geochemistry, Woods Hole, MA, USA.
authors.forename: Christoph
authors.initials: C
authors.lastname: Aeppli
authors.affiliation: Woods Hole Oceanographic Institution, Department of Marine Chemistry and Geochemistry, Woods Hole, MA, USA; Department of Earth Science, University of CaliforniaSanta Barbara, CA, USA.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Carmichael
authors.affiliation: Woods Hole Oceanographic Institution, Department of Marine Chemistry and Geochemistry, Woods Hole, MA, USA; Environmental Chemistry Modeling Laboratory, Swiss Federal Institute of Technology at Lausanne, Lausanne, Switzerland.
authors.forename: Jonas
authors.initials: J
authors.lastname: Gros
authors.affiliation: Woods Hole Oceanographic Institution, Department of Marine Chemistry and Geochemistry, Woods Hole, MA, USA.
authors.forename: Karin L
authors.initials: KL
authors.lastname: Lemkau
authors.affiliation: Woods Hole Oceanographic Institution, Department of Marine Chemistry and Geochemistry, Woods Hole, MA, USA.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Nelson
authors.affiliation: Woods Hole Oceanographic Institution, Department of Marine Chemistry and Geochemistry, Woods Hole, MA, USA.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Reddy
mesh_terms: D002849:Chromatography, Gas; D052918:Environmental Restoration and Remediation / Q000379:methods; D010084:Oxidation-Reduction; D010578:Petroleum / Q000032:analysis*; D059392:Petroleum Pollution; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D014887:Weather
chemical_list: D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical
keywords: Biodegradation; Chemometrics; Comprehensive two-dimensional gas chromatography; Oxygenated hydrocarbons; Partial least squares; Photo-oxidation