Poly(alizarin red S) modified glassy carbon electrode for square wave adsorptive stripping voltammetric determination of metronidazole in tablet formulation

Abstract

Potentiodynamically fabricated poly(alizarin red s) modified GCE was characterized using CV and EIS techniques. In contrast to the cyclic voltammetric response of the unmodified GCE for metronidazole, an irreversible reduction peak with three-folds of current enhancement and reduced overpotential at the poly(alizarin red s) modified GCE showed the catalytic effect of the modifier towards reduction of metronidazole. While observed peak potential shift with increasing pH (4.0–10.0) indicated the involvement of protons during the reduction of metronidazole, peak potential shift with scan rate (20–300 mV s-1) confirmed the irreversibility of the reduction reaction of metronidazole at the modified GCE. A better correlation for the dependence of peak current on scan rate (r2 = 0.9883) than on square root of scan rate (r2 = 0.9740) supplemented by slope value of 0.38 for plot of log(current) versus log(scan rate) indicated the reduction reaction of metronidazole at the surface of the modified electrode was predominantly adsorption controlled. Under the optimized method and solution parameters, reductive current response of tablet sample showed linear dependence on spiked standard concentration in a wide range (0–125 μM) with excellent determination coefficient r2, LoD and LoQ of 0.9991, 0.38, and 1.25 μM, respectively. Spike recovery of 97.9% and interference recovery of 96.2–97.5% in the presence of 21.28 and 31.92 μM of uric acid and ascorbic acid validated the applicability of the present method for determination of metronidazole in tablet formulation. The metronidazole content of the tested tablet formulation using standard addition method was found to be 97.6% of what is claimed by the tablet manufacturer making the developed method an excellent potential candidate for its applicability to determine metronidazole in real samples with complex matrix.

Determination of Lead(II) and Cadmium(II) in Selected Commercially Available Water‐Based Paints of Ethiopia by Anodic Stripping Voltammetry Using a Bismuth‐Modified Glassy Carbon Electrode

“…Accordingly, the calculated K app values shown in Table 3 depict that the K app value of BiGCE is 7.7 times higher than that of the GCE. This indicates that BiGCE has low charge transfer resistance, hence the bismuth modification improved conductivity and the electron transfer rate between a working electrode and solution interface [18] …”

“…As seen in the table, the anodic and cathodic peak currents of BiGCE are 1.2 and 1.19 larger than GCE. This indicated that bismuth modification resulted in an enhanced electron transfer from the [18] …”

“…This indicates that BiGCE has low charge transfer resistance, hence the bismuth modification improved conductivity and the electron transfer rate between a working electrode and solution interface. [18] Square wave anodic stripping voltammetry response of bare and bismuth-modified glassy carbon electrode for the determination of Pb(II) and Cd(II)…”

Review—Novel Trends in the Determination of Pharmaceutical Compounds Commonly Found in Topical Treatments using Electrochemical Sensing Approaches

“…A single sensor modified with the conductive polymer poly (alizarin red S) (PARS/GCE), was proposed by Dawit's team. 70 Another series of modifiers are metallic-based compounds like oxides and other derivatives. Darbandi [71][72][73][74][75][76] Among these sensors, it can be observed that the GCE/MoS 2 exhibits the lowest LOD and the widest dynamic range, due to an increased surface area, surface defects, edge effects, and a decreased charge transfer resistance that enables and enhances electron transfer.…”

Study on Metronidazole Acid-Base Behavior and Speciation with Ca2+ for Potential Applications in Natural Waters

“…In the literature, the use of different techniques was reported for separation or quantitative MNZ detection in environmental and biological samples, human plasma, drugs, and food products. They include high-performance liquid chromatography [ 11 ], liquid chromatography-tandem mass spectrometric method (LC-MS/MS) [ 12 ], chemiluminescence [ 13 ] fluorescence [ 14 , 15 ], near-infrared spectrophotometry (NIRS) [ 16 ], spectrophotometry [ 17 , 18 , 19 ], voltammetry with chemically modified electrodes [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ].…”