Trace determination of gatifloxacin in pharmaceutical and biological samples using hydrophobic magnetic nanoparticles-assisted ionic liquid microextraction coupled with spectrofluorimetry

A simple and rapid microextraction procedure based on the application of magnetic nanoparticles and hydrophobic 1-Hexylpyridinium hexafluorophosphate (Hpy)(PF6) ionic liquid was applied, to trace determination of gatifloxacin. A mixture of (Hpy)(PF6) and magnetic nanoparticles was injected into the sample solution containing the analyse of interest and a cloudy solution was formed. After centrifuging, the sediment phase containing enriched analyse was determined by spectrofluorimetry. Magnetic nanoparticles used in this microextraction procedure significantly improved the extraction recovery, which is due to its proper hydrophobicity. (Hpy)(PF6) was used as the extraction solvent due to some physicochemical properties, such as high hydrophobicity, water immiscibility and quite viscosity. Under optimum experimental conditions, the proposed method provided a limit of detection of 0.09 μg L^sup -1^ and a relative standard deviation of 3.0%. The present technique was applied to gatifloxacin determination in pharmaceutical formulations and human urine.