Ionic liquid based dispersive liquid–liquid microextraction followed by RP-HPLC determination of balofloxacin in rat serum

Abstract

An efficient and environmentally friendly ionic liquid based dispersive liquid–liquid microextraction procedure for the determination of balofloxacin in rat serum by reverse phase high-performance liquid chromatography was developed and validated. The effects of ionic liquids, dispersive solvents, extractant/disperser ratios and salt concentrations on sample recovery and enrichment were studied. Among the ionic liquids investigated, 1-butyl-3-methylimidazolium hexafluorophosphate was found to be the most effective and the recovery was 99.5% at an extractant/disperser ratio of 0.43 by addition of 5.0% NaCl. A threefold increase in detection (0.01 μg mL⁻¹) and quantification (0.035 μg mL⁻¹) limits was achieved when compared to protein precipitation. A linear relationship in the range of 0.04–10.0 μg mL⁻¹ with a correlation coefficient of (r²) 0.9998 was observed. The method was validated and applied to study the pharmacokinetics of balofloxacin in rat serum.