RESUMO
Sparfloxacin (SPFX) can be oxidized by nitrous acid then react with chlorohydric acid further to form a strong fluorescence substance in acid media. The molecular structure is identified by elemental analysis, IR, MS and fluorescence spectra. The emission properties of sparfloxacin and chloro-sparfloxacin are greatly distinct, the fluorescence of sparfloxacin is so weak that it can not be determined by means of fluorescence spectra, but the fluorescence intensity of the new substance is 110 fold more than that of sparfloxacin itself. With quinine sulfate (0.05 mol.L-1 of H2SO4, phi f = 0.55) as standard solution, the fluorescence quantum production rate of SPFX and this new fluorescence were determined as 0.0072 and 0.1539, respectively. By this, a new sensitive method for the determination of SPFX tablets by fluorescence spectroscopy is presented with good result. The recovery of method is 97.2%. RSD is 1.6%. Finally, the fluorescence self quenching and chloro-sparfloxacin enhancement mechanism of sparfloxacin are explored in detail.
