Analytical and mechanistic aspects of the room-temperature fluorescence and phosphorescence of benzo(ƒ)quinoline adsorbed on silica gel chromatoplates with humidified gases

Abstract

The solid-matrix room-temperature fluorescence and room-temperature phosphorescence properties of benzo(ƒ)quinoline adsorbed on silica gel chromatoplates were investigated over a wide range of humidities in N 2, air and O 2. Both neutral and acidic conditions were used and even at the highest relative humidity used, 93% relative humidity, the room-temperature fluorescence and phosphorescence intensities from benzo(ƒ)quinoline were not totally quenched. However, in all experiments, the room-temperature phosphorescence was much more sensitive to humidity quenching than the room-temperature fluorescence. The results gave rather detailed information on quenching of the room-temperature fluorescence and phosphorescence in the different gases at a variety of humidities. It was possible to calculate the contribution to the percent decrease in luminescence due to moisture or a quenching gas. Thus, a more detailed assessment could be made about the quenching of moisture and individual quenching gases on the solid-matrix fluorescence and phosphorescence.