Analysis of polycyclic aromatic hydrocarbons in HPLC fractions by laser-excited time-resolved Shpol'skii spectrometry with cryogenic fiber-optic probes.

Laser-excited time-resolved Shpol'skii spectrometry at liquid helium temperature (4.2 K) is presented for the analysis of polycyclic aromatic hydrocarbons in high-performance liquid chromatography fractions. Fluorescence measurements are rapidly done with the aid of a fiber-optic probe, pulsed tunable dye laser, spectrograph, and intensified charge-coupled device. Analyte identification and peak-purity checking are made through wavelength-time matrix formats, which give simultaneous access to spectral and lifetime information. Sample preparation is rapid and simple. It involves liquid-liquid extraction or solid-liquid extraction of chromatographic fractions at the tip of the fiber-optic probe. The potential of both approaches is demonstrated with the semi-quantitative analysis of priority pollutants in heavily contaminated water samples.