High Resolution Mass Spectrometry Advances in Oil Spill Analysis

Abstract Oil is a complex mixture of alkanes, cycloalkanes, aromatics, nitrogen/sulfur/oxygen (N/S/O) heterocycles, alcohols, ketones, carboxylic acids, porphyrins, and myriad possible combinations therein. Once introduced into the environment, some weathering processes reduce this complexity through evaporative losses (loss to atmosphere) as well water washing low ring number N/S/O acids seawater). However, Gulf Mexico Research Initiative (GoMRI) supported research has revealed that contributions these mechanisms reduction molecular are dwarfed by oxidative (photo- bio-oxidation) increase compositional transformed oil. Because an already analytically challenging organic boiling point species higher than precursors, conventional analytical techniques yield little insight identification oil spill transformation products. Despite challenge, recent advances in science now allow molecular-level systems irrespective initial (unaltered) or transformed-product point; were largely made GoMRI efforts. They expose continuum oxidized products span oil-soluble, oil-soluble interfacially-active, water-soluble species. The isolation characterization interfacially-active confirm long-standing theory photo-oxidation generates surfactant-like species, which limit effectiveness dispersants. Furthermore, specific microcosms shown generate unique also found field samples. Bio-oxidation only very different, species; thus, implicated formation field. Finally, analyses photooxidized distillate cuts asphaltene samples prior reports photo-induced polymerization photo-cracking native petroleum molecules. Here, we summarize understanding over past 8 years, context science, high resolution mass spectrometry, highlight potential opportunities for future research, knowledge gaps must be addressed spills.