Application of fluorescence and PARAFAC to assess vertical distribution of subsurface hydrocarbons and dispersant during the Deepwater Horizon oil spill

Abstract

We evaluated the use of excitation and emission matrix (EEM) fluorescence and parallel factorial analysis (PARAFAC) modeling techniques for monitoring crude oil components in the water column. Four of the seven derived PARAFAC loadings were associated with the Macondo crude oil components. The other three components were associated with the dispersant, an unresolved component and colored dissolved organic matter (CDOM). The fluorescence of the associated benzene and naphthalene-like components of crude oil exhibited a maximum at ∼1200 m. The maximum fluorescence of the component associated with the dispersant (i.e., Corexit EC9500A) was observed at the same depth. The plume observed at this depth was attributed to the dispersed crude oil from the Deepwater Horizon oil spill. Results demonstrate the application of EEM and PARAFAC to simultaneously monitor selected PAH, dispersant-containing and humic-like fluorescence components in the oil spill region in the Gulf of Mexico.

Environmental effects of the Deepwater Horizon oil spill: A review

“…Based on the good experience from the DWH spill, Caruso et al (2013) suggested that SAR should be used more in direct spill response activities and to optimize available response resources. Several studies have used fluorescence excitation-emission matrix spectra and parallel factor analysis techniques (EEM-PARAFAC) for detecting oil degradation products in deep-water or surface-water samples from NGOM (Bianchi et al, 2014;Mendoza et al, 2013;Zhou et al, 2013a;Zhou et al, 2013b). The technique can detect oil derivatives which are transformed into the dissolved organic matter (DOM) pool, no longer recognizable as oil or oil derivatives by traditional HC analyses.…”

Solvent effects in the extraction and detection of polycyclic aromatic hydrocarbons from complex oils in complex environments

“…Our investigations focused on crude oil samples collected from oil spill sites and crude seawater from the Narragansett Bay, with 10 mM of various cyclodextrins dissolved in the seawater. The chemical profile of oil spill oil collected directly from a Gulf of Mexico site has been well characterized in a number of references [26,27] and been shown to contain a diverse mixture of organic compounds including polycyclic aromatic hydrocarbons and a variety of more polar oxygenated metabolites [28]. Tar ball components have been similarly well-characterized using a variety of spectroscopic techniques [29][30][31].…”

Dissolved organic matter dynamics in surface waters affected by oil spill pollution: Results from the Serious Game exercise

“…PAHs are photochemically reactive and have peculiar fluorescence properties, that make them part of both chromophoric DOM (CDOM) and fluorescent DOM (FDOM) (Christensen et al, 2005;Ferretto et al, 2014;Mendoza et al, 2013. CDOM is defined as the fraction of DOM capable of absorbing light at the visible and UV wavelengths, while FDOM is the fraction of CDOM capable of fluorescence.…”