β-CYCLODEXTRIN MODIFIED CARBON PASTE ELECTRODE FOR THE DETERMINATION OF GEMIFLOXACIN AND NADIFLOXACIN

Abstract

The electrochemical behavior of Gemifloxacin (GF) and Nadifloxacin (NF) at β-Cyclodextrin modified carbon paste electrode has been studied. Compared with carbon paste electrode, the β-Cyclodextrin modified carbon paste electrode exhibited a marked enhancement of current response of Gemifloxacin and Nadifloxacin. A simple, precise, inexpensive and sensitive voltammetric method has been developed for the determination of the cited drugs. Cyclic Voltametry studies in Britton Robinson buffer indicate that the process was irreversible and diffusion controlled with some adsorption character. Differential pulse voltammetry (DPV) was used to determine Gemifloxacin and Nadifloxacin in the pure form. The adsorptive stripping response was evaluated as a function of some variables such as pH, the scan rate and accumulation time. The peak current varied linearly for GF and NF in the following range: 5.0x10-8 to 2.0x10-7 mol l-1. The limits of detection (LOD) were 1.2x10-8, 1.0x10-8 mol l-1, while the limits of quantification (LOQ) were 4.3x10-8, 3.3x10-8 mol l-1 for GF and NF, respectively. The percentage recoveries were found in the following ranges: 99.57-100.36% and 99.85-100.64% for GF and NF, respectively. The relative standard deviations were found in the following ranges: 0.426-0.828% and 0.316-0.937% in case of GF and NF, respectively.