Standards for Nanosecond Fluorescence Decay Time Measurements

Abstract

With a synchronously pumped dye laser as excitation source for fluorescence decay time measurements with single-photon counting detection, a critical reevaluation of literature fluorescence decay parameters for “standard” compounds is made and new standards are proposed for lifetime measurements. These are 2,5-diphenyloxazole (PPO), 1-cyanonaphthalene, 1-methylindole, 3-methylindole, 1,2-dlmethylindole, and N,N-dimethyl-1-naphthylamine, in cyclohexane, hexane, or ethanol solution, covering an emission wavelength range of 330 to 440 nm and decay time range of 1.28 to 18.23 ns. Anthracene in solution may also be used as a standard if care is taken with purification and the concentration is known. Quinine bisulfate should not be used as a decay time standard. 1-Cyanonaphthalene provides a convenient standard for gas-phase experiments. © 1983, American Chemical Society. All rights reserved.