Patent ID: 7560711

Claim:
A method for characterization and fingerprinting of petroleum oils using normalized time-resolved laser-induced fluorescence comprising the steps of: exposing an unknown petroleum oil sample to a pulse of ultraviolet laser radiation; simultaneously exposing a plurality of known petroleum oil samples to a pulse of ultraviolet laser radiation by a single laser; measuring the intensities of resulting fluorescence over the spectrum of wavelengths of light from said petroleum oil samples at specific narrow time gates of between about 2 to about 5 nanoseconds within the temporal response of said laser pulse to form a wavelength-resolved fluorescence spectrum for each of said samples; sorting the resulting intermingled wavelength-resolved fluorescence spectra into a plurality of individual fluorescence spectra; normalizing said wavelength resolved fluorescence spectrums at a particular emission wavelength; measuring the spectral subtractions of the known petroleum oil samples wavelength-resolved laser-induced fluorescence spectrum relative to those of the known petroleum oil samples to produce a plurality of resulting fingerprints; and comparing the resulting fingerprints; characterizing said unknown petroleum oil sample based on similarities of its resultant plots with those of said known petroleum oil sample.