Photochemical fluorescence enhancement of terbium-fleroxacin system and determination of fleroxacin

The sensitized fluorescence of the terbium ion(Tb3+) can be observed when e xcited in the presence of fleroxacin(FLRX) in the aqueous solution because a Tb3+-FLRX complex was formed. The sensitized fluorescence was greatly enh anced after the complex system was irradiated by 365nm ultraviolet light. T he irradiation makes the complex system undergo photochemical reactions and a new terbium complex which is more favorable to the intramolecular energy transfer is formed. On this basis a new sensitive and selective photochemi cal fluorimetric method for the determination of FLRX was developed. Under the optimum experimental conditions, the linear range of the determination is 1.0-200x10(-7) mol l(-1) for FLRX, and the detection limit is 1.2x10(-8) mol l(-1). Without any pretreatment the recoveries of FLRX in human urine s amples were determined with satisfaction.