Experimental and Theoretical Study on the Electrochemical Behavior of Zofenopril and its Voltammetric Determination

Abstract

The HPLC-UV method previously developed for the analysis of the flavonoid 2"-O-rhamnosylswertisin (I), an active compound of dried leaf extracts of Aleurites moluccana L. Willd, was fully validated with the inclusion of another flavonoid, swertisin (II). The stability-indicating capability of the method was established by analyzing forced degradation extract samples (acid, alkali, neutral, oxidative and photolytic condition) in which the spectral purity of the markers was ascertained together with the separation of degradation products from the markers. The method proved be linear over a range of 5.89-117.8 and 1.38-27.68 g.mL -1 for I and II, respectively. The recovery for I and II was 100.3 and 102.8%, respectively, at a level of 100%. A relative standard deviation (RSD%) < 1.0% (intra-day) and < 3.5% (inter-days) for area, and less than 0.5% for retention time indicated that the precision of the method is acceptable. Validation parameters such as selectivity and robustness were also determined. In addition, during the course of LC-MS n analysis three other flavonoids were discovered in the A. moluccana extract and their tentative structures identified.

Voltammetric determination of paracetamol in tablet formulation using Fe (III) doped zeolite-graphite composite modified GCE

“…2C) indicated that the reaction was influenced by both the adsorption of the analyte on the surface of the modified electrode and diffusion mode of mass transport. This was also supported by the slope value 0.78 of plot of log of oxidative peak current versus log of scan rate which is above 0.5 for diffusion and 1.0 for adsorption [31]. To evaluate the extent adsorption influences the kinetics of the oxidation reaction of PCT, the current response of the electrode was monitored as a function of time exposure to 1 mM PCT in pH 7 PBS (Fig.…”

Electrochemistry of cefditoren pivoxil and its voltammetric determination

“…For oxidation processes on GCE, shifting of peak potential to less positive potentials with increasing pH may be caused by the initial deprotonation of a functional group before electron transfer. Besides, shifting of reduction peak potential to more negative (more cathodic) values with increasing pH on HMDE may be concluded as presence of protonation step before electron transfer (Tas ßdemir et al, 2012;Pamuk et al, 2013;Zorluog˘lu et al, 2013).…”

“…Calibration parameters were assessed in least-square approach and results were given in Table 1 with repeatability values as well as values of LOD and LOQ calculated using equations given in the literatures (Tas ßdemir et al, 2012;Pamuk et al, 2013;Zorluog˘lu et al, 2013). As could be seen in Table 1, method proposed for GCE has coefficient of determination (R 2 ) higher than 0.98.…”

“…Then the same procedures given in our previous studies (Tas ßdemir et al, 2012;Pamuk et al, 2013;Zorluog˘lu et al, 2013) were followed to prepare tablet solutions and serum samples.…”

“…In this instance evaluation of electrochemical parameters of CTP may be of great importance. Theoretical calculations by which molecular orbitals could be mapped according to their relative energies were also found to be useful as a value added tool to enlighten oxidation-reduction mechanisms by (Tas ßdemir et al, 2012;Pamuk et al, 2013;Zorluog˘lu et al, 2013).…”