Dynamic quenching of fluorescence spectra: The kinetics of solution deoxygenation by purging with an inert gas

CHED 301

Kyle Edenzon and Todd Pagano, tepnts@rit.edu. Laboratory Science Technology program, Rochester Institute of Technology/ National Technical Institute for the Deaf, 52 Lomb Memorial Drive, Rochester, NY 14623
In accordance with the Stern-Volmer equation, dynamic quenching of fluorescence spectra involves the non-radiative deexcitation of a fluorophore through collisions with a quencher (often dissolved oxygen) during the fluorophore's lifetime. In order to avoid problems associated with the quantitative analysis of obtained fluorescence data in the presence of dynamic quenching by oxygen, a method of purging solutions with an inert gas is typically applied. Purging methods remove dissolved oxygen from solutions in accordance with Henry's Law. This kinetic investigation focuses on the purging of anthracene (and related compounds) in cyclohexane with nitrogen gas. Steady-state fluorescence, absorbance, and fluorescence lifetime data are simultaneously collected throughout the study with a novel fiber-optic based instrumental set-up. Optimal purging conditions for the deoxygenation of solutions are described for the systems studied.