Spill it: Measuring oxidative change in oil via Fourier transform infrared spectroscopy

Since its release into the environment on April 20, 2010, oil from the Deepwater Horizon spill has been extensively studied to assess how it changes in the environment over time. The major factors affecting oil degradation are most likely the presence of light (photooxidation) and the presence of microbes (biodegradation). This study aimed to explore these mechanisms by Fourier-transform infrared spectroscopy (FT-IR) and gas chromatography flame ionization detection spectroscopy (GC-FID). To this end, fresh surrogate oil and previously weathered oil collected from Gulf of Mexico (GoM) coast beaches were incubated with seawater in the presence and absence of sunlight and/or biology. Raw oil was monitored over 21 weeks. Though these weathering analogues were not stringent enough to yield oxidative change on levels seen in environmental samples, FT-IR was able to detect subtle changes in oxygenated functional groups. Oil soaked sand patties were monitored for 42 weeks. OSPs appeared to not weather during the incubation. Combined, these results support the idea that FT-IR, while potentially useful in conjunction with other analytical methods should not be used as the sole preliminary screening tool to test oxidative weathering of marine oil