Remote fingerprinting of crude oil using time-resolved fluorescence spectra

The first application of a recently established method of intensity-normalized time-resolved fluorescence (TRF) techniques in the identification of crude petroleum oils in remote sensing is introduced. The excitation wavelength was that of a pulsed Nd:YAG laser at λ = 355nm, and the resulting TRF spectra, measured at specific time-gates, were used to construct fingerprints that reflect only the shapes of the TRF spectra. The method is found to be sensitive enough to discriminate between crude oils of different grades in remote sensing even though the 355nm wavelength is not the optimum wavelength for fluorescence excitation of crude oil. Fingerprints of four crude oils of different grades have been constructed using TRF spectra measured at 5ns time-gate widths and a trend in the fingerprints relating to the crude oils' grades has been found and described.