Development of a flow‐injection analysis system with fluorescence detection for gatifloxacin determination in organized medium

This work reports the development and optimization of a flow injection analysis system with fluorescence detection (FIA–FLUO) for gatifloxacin (GFX) determination in organized medium. The analytical system was based on the enhanced fluorescence of gatifloxacin in micellar medium containing sodium dodecyl sulfate (SDS) at pH 6.0. The influence of physical (carrier flow rate, sample volume and volume of reaction coil) and chemical (pH, concentration of buffer and concentration of SDS) parameters that could affect the performance of the FIA system was evaluated in order to reach optimum conditions in terms of sensitivity and analytical throughput. Under optimized conditions, the FIA–FLUO system allowed the injection of 40 samples per hour with a limit of quantification of 72 µg/L and a RSD of 3.5% at 0.20 mg/L. Real samples of commercial pharmaceutical formulations containing GFX were analyzed, and no statistical difference was observed between the results obtained using the developed system and those obtained using the reference method based on high‐performance liquid chromatography with UV detection. Copyright © 2014 John Wiley & Sons, Ltd.