Analytical Capabilities of Coulometric Sensor Systems in the Antioxidants Analysis

Abstract

The definition of antioxidants (AOs), their classification and properties as well as electrochemical sensor systems for AOs analysis are briefly discussed. The analytical capabilities of coulometric titration with electrogenerated titrants as sensor systems for AOs determination have been considered in detail. The attention focused on the individual AO quantification that was mainly used in the pharmaceutical analysis and estimation of total antioxidant parameters (total antioxidant capacity (TAC), ferric reducing power (FRP) and ceric reducing/antioxidant capacity (CRAC)) allowing the fast screening of the target samples including their quality control. The main advantages of coulometric sensor systems are pointed out. The selective quantification of individual AO in a complex matrix using a combination of chromatography with coulometric or coulometric array detection under potentiostatic mode is discussed. The future development of coulometric sensor systems for AOs analysis is focused on the application of novel coulometric titrants and the application of coulometric detection in flow injection analysis.

Constant–Current Coulometry with Electrogenerated Titrants as a Novel Tool for the Essential Oils Screening Using Total Antioxidant Parameters

“…Summarizing that mentioned above, development of simple, reliable and cost-effective electrochemical approaches for the evaluation of total antioxidant parameters of essential oils is of practical interest. Constant–current coulometry with electrogenerated titrants has been shown to be a powerful tool for the estimation of total antioxidant parameters of different types of foodstuffs, biological fluids, spice extracts, and phytopharmaceuticals [ 25 ]. Halogens (iodine, bromine, and chlorine) and hypohalogenite ions are used as coulometric titrants.…”

“…Halogens (iodine, bromine, and chlorine) and hypohalogenite ions are used as coulometric titrants. Halogens are generated from halogenides in acidic medium, while hypohalogenites in basic medium [ 25 , 26 ]. Electrogenerated halogens differ by oxidative strength, which is increased in the order iodine < bromine < chlorine.…”

“…Bromine acting as an oxidant of average strength is the most suitable for evaluating the antioxidant properties of various samples. Iodine is too weak an oxidant and does not react with many antioxidants [ 25 ]. On the contrary, chlorine is a very strong oxidant leading to deep transformation of the antioxidants as well as to the side reactions that is reflected in the irreproducible stoichiometric coefficients of the titration [ 27 ].…”

Novel Electrodes Based on the Electropolymerized Nanocoatings for the Selective Voltammetric Quantification of Flavanones

“…Among the wide range of analytes, natural phenolic antioxidants, being a part of the daily human diet and medicinal therapy, are of great interest and widely investigated in life sciences. Given that their antioxidant effects are caused by electron transfer reactions, electrochemical methods are often used for their determination [4,5]. Flavanones-flavonoids of Citrus fruits [6]-are less investigated and almost out of consideration in electroanalysis in comparison to other natural phenolics.…”

“…Proc. 2022, 9, x FOR PEER REVIEW 2 of 7 electrochemical methods are often used for their determination [4,5]. Flavanones-flavonoids of Citrus fruits [6]-are less investigated and almost out of consideration in electroanalysis in comparison to other natural phenolics.…”