Hydrocarbon Detection, Characterization, and Spectral Fingerprinting in the Marine Environment

As a result of increased oil exploration and an increased risk of oil spills in the marine environment, the ability to detect and characterize spilled oil with spectral fingerprinting has major significance. First, a spectrometer and fluorometer were used to characterize and compare spectral properties of parent polycyclic aromatic hydrocarbon (PAHs) and their alkylated homologs in relation to oil and the weathering processes. Next, prepared parent PAH compounds were tested for sensor responses to seven commercially available off-the-shelf instruments with varying optical parameters that measure the fluorescence of hydrocarbon molecules. Lastly, the seven fluorometer responses were tested in response to oil in water solutions. From absorbance and Excitation Emission spectra, the spectral properties of parent and alkylated PAHs are very similar. For each parent PAH, the Cl-Alkylated homolog had a lower concentration and less defined absorbance spectrum than the parent PAH. The Chelsea UviLux and Cyclops-7 Refined Oil sensors had an extremely linear and sensitive response to Fluorene. The C3-Crude Oil fluorometer surprisingly did not have strong response to the 1.4 g/L North Sea Crude water accommodated fraction. The Chelsea UviLux T-Piot sensor output detects lower concentrations of oil in water and provides higher resolution data than the DAQ Plotter for both water accommodated and chemically dispersed solutions.