Adsorptive Stripping Voltammetric Determination of Fluoroquinolones in Pharmaceuticals
AMBER R. SOLANGI1, M. Y. KHUHAWAR2* AND M. I. BHANGER1
1. National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan
2. M. A. Kazi Institute of Chemistry, University of Sindh, Jamshoro, Pakistan
(Received: December 30, 2004; Accepted: February 26, 2005)
ABSTRACT
Sensitive cathodic stripping voltammetric methods have been developed for two fluoroquinolone antibacterial drugs, norfloxacin and enoxacin. Dimethylformamide (DMF) and 0.1 M hydrochloric acid were used as media for norfloxacin and enoxacin respectively. Potassium chloride was used as base electrolyte. A reduction wave was observed for norfloxacin within the range of -1.02 to -1.13 V and for enoxacin within -0.93 to -1.07 V. Linear calibration ranges for norfloxacin and enoxacin were observed within 20-100 μg/mL and 1-40 μg/mL with detection limits of 10 μg/mL and 50 ng/mL respectively. Relative standard deviations (RSD) for the analysis of 10 μg/mL norfloxacin and 10 μg/mL enoxacin (n = 5) were observed 1.1% and 0.2%. The presence of glucose, lactose, sorbitol, gum arabic, starch, magnesium stearate, methylparaben and propylparaben did not affect the determination. The methods were used for the analysis of pharmaceutical preparations and quantitative recoveries were obtained with relative deviation within 1.6-4.75%.
Key words: fluoroquinolone, norfloxacin, enoxacin, adsorptive stripping voltammetry (AdSV)