High-performance liquid chromatographic separation of polycyclic aromatic hydrocarbons using pyridinium chloride as a selective fluorescence quencher to aid detection.

The first use of pyridinium chloride (PC), as a selective fluorescence quenching agent of alternant polycyclic aromatic hydrocarbons (PAHs), under HPLC separation conditions is reported. PC was found to be superior to nitromethane, the only reported PAH selective quencher used in HPLC. The mobile phase addition of 0.03 M PC greatly simplifies the observed fluorescence-detected chromatograms for complex PAH mixtures, facilitating PAH identification. Stern-Volmer quenching constants (K(sv)) for PAHs were calculated from the chromatograms obtained under isocratic and gradient conditions and found to be similar. The K(sv) values were shown to be useful in establishing peak purity.