| Abstract |
Fluorescence spectra, quantum yields, and concentration dependencies are reported for five representative polycyclic aromatic hydrocarbons (PAH) in water to ascertain the applicability of measuring PAH in aqueous systems by spectrofluorimetry. The fluorescence quantum yields of benzene, naphthalene, anthracene, pyrene, fluoranthene, and benzo(e)pyrene in water are, respectively, 5.3 + or - 0.5 x 10 to the -3rd power, 0.16 + or - 0.02, 0.25 + or -0.02, 0.69 + or - 0.06, 0.20 + or - 0.01, and approximately 0.3 + or - 0.1. With the exception of pyrene, oxygen quenching of the fluorescence in water is at most 30%. The fluorescence concentration dependence was measured by photon counting the fluorescence intensity relative to the excitation light intensity. All the PAH fluorescences exhibited a linear dependency on the concentration. For a fluorescence signal-to-noise ratio of 1, the detection limits are as follows: naphthalene, 0.03 micrograms/l., anthracene, 0.03 micrograms/l., pyrene, 0.15 micrograms/l., fluoranthene, 0.17 micrograms/l., and benzo(e)pyrene, 0.10 micrograms/l. Copyright (c) 1976 by the American Chemical Society. |
