Comparison of the Electroanalytical Oxidation of Ritodrine Hydrochloride at Carbon Paste, ZrO2 Nano Particles Modified, Graphite Pencil and Glassy Carbon Electrodes

Electrochemical oxidation behavior of ritodrine hydrochloride (RT.HCl) was studied in Britton Robinson buffer at different pH range from 2 to 10 using carbon paste (CPE), modified zirconium oxide carbon paste (ZrO2-MCPE), graphite pencil (GPE) and glassy carbon electrodes (GCE). Cyclic voltammetry (CV) was showed one well-defined, irreversible, diffusion-controlled anodic peak at pH 9 by using CPE and GPE electrodes and pH 8 and 7 at ZrO2-MCPE and GCE electrodes, respectively. The linear response was obtained in the concentration range of 3.33×10-6-4.33×10-5, 6.67×10-8-7.33×10-7, 4.0×10-6-6×10-5 and 5.0×10-6-4×10-5 M with detection limit (LOD) of 1.57×10-6, 6.18×10-8, 1.71×10-6 and 3.32×10-6 mol L-1 by using differential pulse voltammetric method (DPV) at CPE, ZrO2-MCPE, GPE and GCE, respectively. The linear concentration response was obtained in the concentration range of 1.33×10-6-1.47×10-5, 3.33×10-8-3.67×10-7, 4.0×10-6-5.5×10-5 and 5.00×10-6-4.5×10-5 M with detection limit (LOD) 5.78×10-7, 1.11×10-8, 1.74×10-6 and 1.84×10-6 mol L-1 by using square wave voltammetric method (SWV) at CPE, ZrO2-MCPE, GPE and GCE, respectively. The repeatability and reproducibility of the method were 0.41-1.27, 0.25-1.11, 0.49-1.86 and 0.73-2.13% relative standard deviations (RSD) for anodic peak current by using square wave voltammetric method (SWV) at CPE, ZrO2-MCPE, GPE and GCE electrodes. The mechanism successfully confirmed by molecular orbital calculation (MOC). These calculations give the bond order, bond length and charge distribution. This helps the successful choice of the weakest bond which changed during oxidation or reduction. Therefore, the best pathway for the oxidation of this drug is correctly selected for proposed mechanism.