The voltammetric behaviour of ellagic acid (EA) is investigated by cyclic, differential pulse and square-wave voltammetry (CV, DPV and SWV, respectively). Based on the anodic oxidation peak at approximately 0.42V in acetic/acetate buffer (pH 5.5) a robust and a highly reliable square-wave voltammetric method is presented for the determination of EA. The oxidation peak current was linearly dependent on the concentration of EA in the range of 1.0×10(-7)-1.5×10(-6)mol/L (r=0.9997), with a detection limit of 1.0×10(-8)mol/L (S/N=3) and a quantification limit of 3.4×10(-8)mol/L (S/N=10), good reproducibility and a satisfactory level of selectivity towards others polyphenols. The proposed method was applied to the determination of free and total EA in fruits, nuts and juices with good analytical results being obtained.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.foodchem.2011.03.064 | DOI Listing |
Methods Protoc
December 2024
Department of Organic and Medicinal Chemistry, Faculty of Pharmacy, University of Pécs, Honvéd Street 1, H-7624 Pécs, Hungary.
An electrochemical investigation of 1,2- and 1,4-dihydroxybenzenes was carried out with platinum macro- and microelectrodes using square wave and cyclic voltammetry techniques. Furthermore, the effect of the two solvents-acetic acid and ethyl acetate-was compared. When using square wave voltammetry, signals only appeared at lower frequencies and only when the supporting electrolyte was in excess, as expected due to the relatively low permittivity of the used solvents.
View Article and Find Full Text PDFAnal Chem
December 2024
Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Ultramicro pipettes with circular orifices have practically become common probes in exploring the microscopic world, yet the versatility of differently shaped pipettes is undermined in the pore family. Herein, ultramicro triangular pipettes with a pseudotriangular-shaped orifice were fabricated by laser-pulling triangular quartz capillaries and characterized by microscopic and electrochemical methods. Then, the differences in the electrochemical behaviors of triangular and circular pores were revealed through experiments and simulations.
View Article and Find Full Text PDFAnal Biochem
December 2024
Department of Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta, 577451, Karnataka, India.
In the present work, a convenient, efficient and disposable electrochemical sensor has been developed by electropolymerizing methylene blue (PMB) on the surface of a pencil graphite electrode (PGE), which facilitates the electrochemical analysis of an antioxidant l-Ascorbic Acid (AA). The structural characteristics of both the methylene blue modified pencil graphite electrode (PMB/PGE) and the bare pencil graphite electrode (BPGE) have been examined using scanning electron microscopy (SEM) in conjunction with energy-dispersive X-ray analysis (EDX). Additionally, the charge transfer behavior has been evaluated using the electron impedance spectroscopy (EIS).
View Article and Find Full Text PDFFoods
November 2024
Department of Biology and Chemistry, Universidad de Sucre, Sincelejo 700001, Colombia.
Due to the lucrative coffee market, this product is often subject to adulteration, as inferior or non-coffee materials or varieties are mixed in, negatively affecting its quality. Traditional sensory evaluations by expert tasters and chemical analysis methods, although effective, are time-consuming, costly, and require skilled personnel. The aim of this work was to evaluate the capacity of a smart electronic tongue (e-tongue) based on a polypyrrole sensor array as a tool for the rapid analysis of coffees elaborated from beans of different varieties.
View Article and Find Full Text PDFHeliyon
October 2024
Department of Chemistry, College of Science, Bahir Dar University, Ethiopia.
A Novel bioanalytical detector based on Poly(Diaquabis(1,10-phenanthroline copper (II) Iodide) (poly([Cu(HO)P]I)/GCE) has been fabricated by potentiodynamic polymerization of [Cu(HO)P]I. The synthesized complex and the fabricated electrodes showed a promising electrocatalytic behavior towards the electrooxidation of Trimethoprim (TPM). Based on the regression coefficient value of scan rate with peak current and square root of peak current, the oxidation of TMP at poly([Cu(HO)P]I)/GCE was dominated by diffusion.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!