Статті
Постійне посилання колекціїhttps://dspace.nuft.edu.ua/handle/123456789/7522
Переглянути
2 результатів
Результати пошуку
Документ The theoretical description for aesculetin and quercetin cathodic electrochemical determination in wines(2023) Tkach, Volodymyr; Paiva Martins, José Inácio F.; Romanova, Zoriana; Paientko, Viktoria; Oliveira, Sílvio C.; Garcia, Jarem; Skrypska, Olha; Ivanushko, Yana; Yagodynets, PetroIn this work, the possibility of cathodical electroanalytical determination of aesculetin and quercetin, the most representative polyphenolic coumarin and flavonoid, is theoretically described. The cathodic reaction is given by the electrochemical reduction of 2- and 4-pyrone rings simultaneously on a vanadium(III) oxyhydroxide-modified electrode at a pH correspondent to wine (3 < pH _ 7). Analysis of the mathematical model, corresponding to the reaction mechanism, lets us conclude that, although the oscillatory behavior remains highly probable, the cathodic electroanalytical process, based on VO(OH)-assisted reaction, may be even more efficient than anodic oxidation of the polyphenolic compounds in the same conditions.Документ Theoretical description of sotolone electrochemical determination in wine in basic media over an undoped conducting polymer(2023) Tkach, Volodymyr; Kushnir, Marta; Kopiika, Vira; Luganska, Olga; Omelyanchyk, Lyudmyla; Kormosh, Zholt; Kucher, Mykhailo; Garcia, Jarem; Palamarek, Karina; Bagrii, Konon; Medvedeva, Anzhelika; Oliveira, Sílvio C.; Yagodynets, Petro; Niyazov, Laziz; Musayeva, Dilfuza; Samadov, Bakhodirjon; Payentko, Viktoriia; Demianenko, Eugeny; Paiva Martins, Jose Inacio Ferrao; Vaz dos Reis, Lucinda; Karputina, Margarita; Khargeliia (Karputina), Daria; Nazymok, Yevgeniya; Ivanushko, Yana; Palytsia, YuliaThe electrochemical determination of sotolone in basic media over an undoped conducting polymer has been described for the first time. The alkaline hydrolysis, breaking the furanonic ring, leads to the appearance of an acid ion, entering the polymer matrix as a dopant. The stability analysis of the system, made by the development and investigation of the correspondent mathematical model, shows that the sotolon electrochemical determination is made efficiently. As for the oscillatory behavior, it may also be caused by the cyclic effect of chemical and electrochemical stages on the double electric layer capacitance and impedance.