Fluorescence Detection and Identification of Nitro Derivatives of Polynuclear Aromatic Hydrocarbons by On-Column Catalytic Reduction to Aromatic Amines

摘要

Nitro-PAHs at trace level concentrations were reduced on-column to corresponding amino PAHs with a platinum/rhodium catalyst in a methanol-water reverse-phase HPLC system. The technique provides a convenient and sensitive method for detecting nitro-PAHs by fluorescence measurements of the corresponding amines. The technique has been incorporated in a simple automated system that eliminates sample cleanup in the determination of selected nitro-PAHs in complex matrices. Detection limit for 1-nitro pyrene is better than 10 pg on-column. Fluorescence spectra of 19 amino PAHs were measured. The catalyst does not change the chemical integrity of the PAHs but induces unknown chemical reactions on polar oxygenated species. The catalyst enhances the intensity of fluorescence emissions of most PAHs by removing quenching effects of dissolved oxygen. The pyrene emission signal is increased eightfold.