title: Electrochemical sensing of total antioxidant capacity and polyphenol content in wine samples using amperometry online-coupled with microdialysis.
abstract: This work describes the method for total antioxidant capacity (TAC) and/or total content of phenolics (TCP) analysis in wines using microdialysis online-coupled with amperometric detection using a carbon microfiber working electrode. The system was tested on 10 selected wine samples, and the results were compared with total reactive antioxidant potential (TRAP), oxygen radical absorbance capacity (ORAC), and  chemiluminescent determination of total antioxidant capacity (CL-TAC) methods using Trolox and catechin as standards. Microdialysis online-coupled with amperometric detection gives similar results to the widely used cyclic voltammetry methodology and closely correlates with ORAC and TRAP. The problem of electrode fouling is overcome by the introduction of an electrochemical cleaning step (1-2 min at the potential of 0 V vs Ag/AgCl). Such a procedure is sufficient to fully regenerate the electrode response for both red and white wine samples as well as catechin/Trolox standards. The appropriate size of microdialysis probes enables easy automation of the electrochemical TAC/TCP measurement using 96-well microtitration plates.
authors: Department of Physical Chemistry, Faculty of Science, Palacký University, Olomouc, Czech Republic.
authors: Petr
authors: P
authors: Jakubec
authors: Martina
authors: M
authors: Bancirova
authors: Vladimir
authors: V
authors: Halouzka
authors: Antonin
authors: A
authors: Lojek
authors: Milan
authors: M
authors: Ciz
authors: Petko
authors: P
authors: Denev
authors: Norbert
authors: N
authors: Cibicek
authors: Jan
authors: J
authors: Vacek
authors: Jitka
authors: J
authors: Vostalova
authors: Jitka
authors: J
authors: Ulrichova
authors: Jan
authors: J
authors: Hrbac
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D002244:Carbon; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D017551:Microdialysis; D008839:Microelectrodes; D059808:Polyphenols / Q000032:analysis*; D014920:Wine / Q000032:analysis*
chemical_list: D000975:Antioxidants; D059808:Polyphenols; D002244:Carbon