Dinuclear copper(II) octaazamacrocyclic complex in a PVC coated GCE and graphite as a voltammetric sensor for determination of gallic acid and antioxidant capacity of wine samples

Abstract

A novel efficient differential pulse voltammetric (DPV) method for determination gallic acid (GA) was developed by using an electrochemical sensor based on [Cu2tpmc](ClO4)4 immobilized in PVC matrix and coated on graphite (CGE) or classy carbon rod (CGCE). The proposed method is based on the gallic acid oxidation process at formed [Cu2tpmcGA](3+) complex at the electrode surface. The complexation was explored by molecular modeling and DFT calculations. Voltammograms for both sensors, recorded in a HNO3 as a supporting electrolyte at pH 2 and measured in 2.5×10(-7) to 1.0×10(-4) M of GA, resulted with two linear calibration curves (for higher and lower GA concentration range). The detection limit at CGE was 1.48×10(-7) M, while at CGCE was 4.6×10(-6) M. CGE was successfully applied for the determination of the antioxidant capacity based on GA equivalents for white, rosé and red wine samples.

Electrochemical Determination of Natural Drug Colchicine in Pharmaceuticals and Human Serum Sample and its Interaction with DNA

“…This can be attributed to the sharp and high potential peak value for the COLC oxidation at BDDE, using the developed procedure. Similar to these compounds, some phenolic compounds (gallic acid, caffeine, chlorogenic acid, vanillin) also do not interfere with COLC determination as at higher pH (such as in this study 7.5) they do not show electrochemical response or they provide broad peak at lower potentials . These compounds usually provide oxidation behavior at potentials lower than 1 V, and this potential with increase of pH is followed with potential shift to more negative potentials.Obviously, DNA also does not interfere with COLC, indicating possible determination of this compound in biological samples (Figure B).…”

Voltammetric determination of polyphenolic content in pomegranate juice using a poly(gallic acid)/multiwalled carbon nanotube modified electrode

“…The estimated TPC value is found to be 277.4 mg L −1 . The observed higher value can be attributed to the fact that all phenols in the real samples can be detected by this method, and furthermore, the Folin–Ciocalteu reagent may react with many nonphenolic substances [ 31 ]. This problem can be resolved by using the sensor since the nonphenolic compounds have no interference with the response of the polyphenols.…”

Highly Selective Electrochemical Determination of Phlorizin Using Square Wave Voltammetry at a Boron-Doped Diamond Electrode

“…Up to now, there are several electroanalytical methods reported for the determination of the total antioxidant capacity (Pekec et al 2013;Rebelo et al 2013;Tirawattanakoson et al 2016;Gao et al 2015;Petkovic et al 2015) and chromatographic methods using different detectors such as highperformance liquid chromatography (HPLC) in combination with electrospray ionization tandem mass spectrometry (Lijia et al 2014), with nuclear magnetic resonance and mass spectroscopy (NMR-MS) (Lommen et al 2000;Tsao et al 2003), Electronic supplementary material The online version of this article (doi:10.1007/s12161-017-0935-x) contains supplementary material, which is available to authorized users.…”