Voltammetric study of secnidazole and its determination in pharmaceutical tablet using 1 , 4-benzoquinone modified carbon paste electrode

ISSN: 2410-9649 Nikodimos et al / Chemistry International 4(1) (2018) 43-51 iscientic.org. 44 www.bosaljournals/chemint/ editorci@bosaljournals.com Considering its huge importance, the SCZ has studied by different approaches like spectrophotometry (Khieret al., 2008; kumar et al., 2012; Sonpetkaret al., 2012; Youssef et al., 2015), HPLC (Baraka et al., 2014; Ali et al., 2016; Sharminet al., 2016) and electrochemical techniques (Radi andHassanein, 2000; El-Sayedet al., 2010; Elqudabyet al., 2013). But most of the conventional methods reported are sensitivity poor, require expensive instruments and a much longer detection time and not environmentally friendly. Therefore, development of other better alternative method which is selective, sensitive, cheap and environmentally friendly is necessary. Recently, electrochemical techniques including cyclic voltammetry, differential pulse voltammetry etc are attracting attention of researchers throughout the world for the detection of pharmaceutical formulations. This is because they provide fast response time and high sensitivity for measuring analytes. Further; they require only compact instruments and straightforward operations (Harvey, 2000). Electrodes modified by polymers have received special attention by researchers in recent years. This is because such electrodes have good stability, reproducibility, increase in active sites, homogeneity in electrochemical deposition and strong adherence to electrode surface (Radhi, 2016). Particularly those electrodes modified by benzoquinone had shown remarkable advantages from their low noise levels and higher sensitivity (Akliluet al., 2008). In this work, SCZ was studied using 1,4-BQMCPE and yielded a well-defined and a very sensitive reduction peak. Compared with that at the bare CPE, the reduction peak increased remarkably. The electrode process was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) and influence of different experimental parameters was studied. Based on this, an electrochemical method which has advantages such as low detection limit, a rapid response, excellent reproducibility simplicity and low cost is proposed for direct determination of SCZ. MATERIAL AND METHODS Instruments and apparatus CHI760D Electrochemical Workstation, (CHI Instruments, USA) was used for all electrochemical measurements. A bare CPE or 1,4-BQMCPE as a working electrode, saturated silversilver chloride (Ag/AgCl, KCl saturated) as a reference electrode and platinum wire as a counter electrode were employed for a conventional three-electrode system. The pH of the buffer solutions was measured with a Jenway model 3310 pH meter (Denver instrument). An electronic balance (Denver instrument) was used for measuring mass of different chemicals and samples. A magnetic stirrer with a hot plate form was used for stirring in pH adjustments. Other materials include; Spatula, filter paper, beaker, wash bottle, Mortar with pestle, volumetric flask of different sizes, micropipette (John Poulten Ltd) and Graduated cylinder. Chemicals and reagents Standard SCZ was purchased from Emmellen Biotech Pharmaceuticals Limited. Britton-Robinson buffer (BRB) solutions were prepared using Boric acid (BIO-lab laboratories LTD), phosphoric acid (Veeni chemicals) and glacial acetic acid(Blulux laboratories reagent) and adjusted to the desired pH with 1.0 M NaOH(Blulux laboratories reagent). 1, 4-Benzoquinone (Riedel-de Haën), graphite powder (BDH-Laboratory supplies Poole) and paraffin oil0.0 -0.3 -0.6 -0.9 -1.2 0 20 40 60 80 100