Selective Voltammetric Detection of Ascorbic Acid from Rosa Canina on a Modified Graphene Oxide Paste Electrode by a Manganese(II) Complex

Abstract

Voltammetric techniques have been considered as an important analytical tool applied to the determination of trace concentrations of many biological molecules including ascorbic acid. In this paper, ascorbic acid was detected by square wave voltammetry, using graphene oxide paste as a working electrode, modified by a film of a manganese(II) complex compound. Various factors, such as the effect of pH, affecting the response characteristics of the modified electrode were investigated. The relationship between the peak height and ascorbic acid concentration within the modified working electrode was investigated, using the calibration graph. The equation of the calibration graph was found to be: I = 0.0550γac + 0.155 with R2 = 0.9998, where I is the SWV current and γac is the mass concentration of ascorbic acid. The LOD and LOQ of the proposed method were determined to be 1.288 μg/L and 3.903 μg/L, respectively. Several compounds, such as riboflavin, biotin, and ions, such as Fe and Cu, were tested and it seemed that they did not interfere with the analytic signal. The proposed procedure was successfully applied in the determination of ascorbic acid in Rosa canina hips.

Different Aspects of the Voltammetric Detection of Vitamins: A Review

“…The method was effective, and no interference from the presence of other substances in the sample was detected. The detection limits were low (1.2888 µg/mL) and the determination of ascorbic acid was successful [ 153 ]. Another study conducted a cyclic voltammetric study of ascorbic acid using a polymelamine/gold nanoparticle modified carbon paste electrode (PM/AuNPs/CPE) in phosphate buffer solution of pH = 7.0.…”

A Theoretical and Experimental Square-Wave Voltammetric Study of Ascorbic Acid in Light of Multi-Step Electron Transfer Mechanism

“…63 Unfortunately, studying the electrochemistry of AA on these unmodified electrodes was often problematic due to the fact that the oxidation products of AA (mainly 2,3-diketogulonic acid) have significant fouling effect on the electrode. 64 This problem was solved with many different activations or modifications on the surface, including vacuum heat activation of the GC, 65 modification with microparticles of Bi 2 O 3 , 66 polypyrrole/dodecyl sulphate (PPy/DS) film, 67 multi-walled carbon nanotubes (MWCNTs) and Nafion membrane, 68 graphene decorated with gold nanoparticles (AuNPs-β-CD-Gra), 69 modification of paraffin-impregnated graphite electrode (PIGE) with polyrutin, 70 modification of graphene oxide paste with Mn(II) complex, 71 modification of gold microelectrodes with Pd 72 and many others. [73][74][75] Regardless of the fact that most of the modifications overcome the problem with fouling, thus corresponding sensors had excellent sensitivity, complexity of various modifications very often can result in a low reproducibility and/or impractical application.…”

Electrochemical Characterization of the Antioxidant Properties of Medicinal Plants and Products: A Review

“…Most approaches are based on the application of pulse modes (DPV and SWV) due to the higher sensitivity compared to the linear sweep mode. Furthermore, adsorptive preconcentration at the open circuit potential [149,150,160,168,170,[177][178][179] allows for improvement of the analytical characteristics of the antioxidants quantification, although it significantly increases the measurement duration (up to 5 min) and can lead to co-adsorption of other components of the sample and complicate the determination.…”

“…Electropolymerized coverages of triphenylmethane dyes and gallic acid act as selective components giving a response to phenolic antioxidants due to the structural similarity [147,151,173]. Metal and bimetal nanoparticles, and metal complexes act on the principle of electrocatalysis and provide quantification of low concentrations of antioxidants [154,165,168,178]. The combination of electrochemically inert metal oxide nanoparticles with surfactants as dispersive agents leads to the formation of stable dispersions with a smaller size of nanoparticles [145,152,186].…”

“…Regarding selectivity, the most impressive data were obtained using electrodes modified with molecularly imprinted polymers [158,172,174]. Although, other electrodes for flavonoids and phenolic acids determination [146][147][148][149][150][151][152][153][154][155][156][157][158][160][161][162][164][165][166][167][168][173][174][175]178] also show high selectivity in the presence of structurally related antioxidants that is caused by the type of modifier and conditions of electrochemical measurements (supporting electrolyte type and pH, electrochemical window, potential scan rate, etc. ).…”