Перегляд за Автор "Ivanushko, Yana"

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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, Petro
In 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.
The theoretical description for sotolone cathodic and anodic electrochemical determination in wines
(2023) Tkach, Volodymyr; Kushnir, Marta; Oliveira, Sílvio C.; Garcia, Jarem; Karputina, Margarita; Khargeliia (Karputina), Daria; Ivanushko, Yana; Morozova, Tetiana; Yagodynets, Petro
Sotolone is a natural aromatizer, present in Portuguese wine. The goal of this work is the mechanistic theoretic analysis of the sotolon electrochemical determination over a conducting polymer electrode.
The theoretical description for sulfite vanadium(III)-oxyhydroxide-assisted electrochemical determination in natural water and beverages
(2022) Tkach, Volodymyr; Kushnir, Marta; Oliveira, Sílvio C.; Garcia, Jarem; Ivanushko, Yana; Nazymok, Yevgeniya; Morozova, Tetiana; Yagodynets, Petro; Khmeliar, Inesa; Kushnir, Lesya; Shahiieva, Raisa; Vitriak, Oksana; Romanova, Zoriana; Grabovska, Olena
Sulfite is the ion of sulfurous acid, correspondent to tetravalent sulfur. It is used as a conservant in food industry and in beverage production. On the other hand, sulfite is an ecological marker for acid rains occurrence, which may be highly (eco)toxic, reason why its determination is really actual. Being a tetravalent sulfur derivative, sulfite may be either oxidized or reduced. In the case of cathodic reduction, the elemental sulfur or sulfide-ion may be a product, depending on pH.
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, Yulia
The 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.