Quantitative Measurements of Individual Polycyclic Aromatic Hydrocarbons in a Mixture by Coherent Anti-Stokes Raman Spectrometry

Abstract

Coherent anti-Stokes Raman spectroscopy (CARS) was used to obtain Raman spectra of selected polycyclic aromatic hydrocarbons (PAHs) composed of between three and seven fused rings when the compounds were pumped in the resonance and pre-resonance regions, a simple mixture of three PAHs could be optically separated through the wavelength selectivity of the resonant enhancement process. The spectrum from a component in the mixture and the spectrum of each pure component showed no significant differences when pumped at the same wavelength. Finally, lineshape analysis performed on the CARS spectra facilitated comparisons between classes of compounds and for quantitative purposes.