Application of a pencil graphite electrode for voltammetric simultaneous determination of ascorbic acid, norepinephrine, and uric acid in real samples

Abstract

A pencil graphite electrode (PGE) was used for the simultaneous detection of ascorbic acid (AA), norepinephrine (NE), and uric acid (UA) by differential pulse voltammetry and cyclic voltammetry. The anodic peaks of AA, NE, and UA in their mixture can be well separated in 0.1 M Britton-Robinson buffer solution at pH 4.0. The effects of various experimental parameters such as pH, scan rate, and voltammetric parameters on the voltammetric response of these compounds were investigated. Under optimum conditions, linear calibration graphs were obtained from the AA, NE, and UA concentration ranges, which were 100-800 nM, 20-170 nM, and 40-175 nM, respectively. The detection limits for AA, NE, and UA were 27 nM, 4 nM, and 10 nM in the form of a mixture at the PGE. This electrode shows great analytical performance characteristics, corresponding repeatability and recovery for the simultaneous determination of these compounds. PGE, which was used for the first time in this method, has been successfully applied for the assay of UA in human urine samples with the aim of determining AA and NE in pharmaceutical drugs.

Recent Developments in Voltammetric Analysis of Pharmaceuticals Using Disposable Pencil Graphite Electrodes

“…These functional groups activate the electrode surface by enhancing its hydrophilic properties [82] and may have an electrocatalytic effect, improving the electron transfer rate for some analytes [83]. The PGE pretreatment reduces the background current [74], and due to the oxidation of the graphite layer, the effective surface area of the electrode is increased [84] by the formation of carbon nanoparticles [81], thus offering better sensitivity and more reproducible results. All these observations were supported by experimental results.…”

“…The analytes' voltametric behavior depends on the PGE's electrochemical treatment (activation) method (at a constant current [62], performed by maintaining the working electrode for a given time at a certain potential [36,37,82,[84][85][86][87][88], or potentiodynamic, being carried out by CV [20,60,68,[89][90][91][92]) as well as on the instrumental parameters (pretreatment time and potential in the potentiostatic procedure and scan rate and potential range in the CV method) and on the nature, concentration, and pH of the supporting electrolyte [14,83]. For example, in the case of diclofenac sodium, the potentiostatic activation resulted in a more pronounced enhancement of the DPV anodic peak in comparison with electroactivation by CV [80].…”

“…By applying DPV to the ET-PGE, well-separated and sharp peaks were obtained for acetylsalicylic acid (ASA), NP, and UA. When the concentration of an analyte was increased while maintaining the concentrations of the other two constant, as well as when the concentrations of all three species were gradually enhanced, the peak currents of all compounds varied linearly, and the slopes of the calibration graphs of each analyte did not change significantly, thus enabling their quantitative simultaneous determination [84].…”

Katyonik Surfaktan Varlığında Kalem Grafit Elektrot Yüzeyinde Epirubisin’in Sıyırma Voltametrisi ile Miktar Tayini

“…Kaynakçada KGE'lerin pek çok uygulaması görülmektedir. İz metal analizleri (Honeychurch 2015), ürik asit, norepinefrin ve askorbik asitin eş zamanlı analizi (Levent and Onal 2018), nikotin analizi (Levent et al 2009), kafein analizi (Ly et al 2004) (Gopinath et al 2018;Dodde et al 2003;Sottani et al 2008;Souza et al 2018). EB'nn elektrokimyasal özellikleri inceleyen ve çeşitli çalışma elektrotları kullanılarak yapılan miktar tayini çalışmaları ise Çizelge 1'de verilmiştir.…”

Novel voltammetric investigation of dipyridamole at a disposable pencil graphiteelectrode

“…PGEs present good electrochemical characteristics and are cheap, easily commercially available, and simple to use. Thus, in recent years this type of electrode has gained even more applicability in voltammetric analysis of pharmaceutically [33][34][35][36][37][38][39] and biologically [40][41][42][43] important compounds.…”