Fluorescence of Aromatic Hydrocarbons in Aqueous Solution

摘要

The fluorescence properties of more than 20 aromatic hydrocarbons in aqueous solution have been characterized. The list includes benzene, toluene, ethylbenzene, and xylenes (BTEX) and naphthalene and its 1- and 2-methyl derivatives. They are found in most fuels and are sufficiently soluble to pose an environmental hazard. The fluorescence of aromatic hydrocarbons is well known, but the work reported here represents the first comprehensive characterization for the aqueous phase. BTEX fluorescence quantum yields are lower in aqueous solution than in organic solvents; a similar, but less pronounced, trend holds for the naphthalenes. Fluorescence lifetimes were determined in a fiber optic light delivery and collection mode similar to that which would be used in field measurements. Stern-Volmer analysis stows that fluorescence quenching by dissolved oxygen and anions at levels expected for environmental samples is small. Interering fluorescence of humic substances is a greater concern.