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Постійне посилання колекціїhttps://dspace.nuft.edu.ua/handle/123456789/7522

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20234

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Автор: search.filters.author.Oliveira, Sílvio C.

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  • Ескіз
    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, 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.
  • Ескіз
    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, 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.
  • Ескіз
    Документ
    The theoretical description of sucralose cathodic electrochemical determination over a poly(safranin) modified electrode in acidic media
    (2023) Tkach, Volodymyr; Storoshchuk, Nataliia; Storoshchuk, Bogdan; Oliveira, Sílvio C.; Kryvetskyi, Viktor; Kryvetska, Inna; Kryvetskyi, Igor; Yemelianenko, Nataliia; Narsiia, Valentyn; Yagodynets, Petro; Silva, Adriano; Masna, Zoriana; Shevchenko, Inna; Gnitsevych, Victoriya; Medvedeva, Anzhelika; Vasylieva, Olena; Musayeva, Dilfuza; Kosimov, Xayriddin; Jabborova, Oysha; Samadov, Bakhodirjon; Sagdullayeva, Gulandom; Hamdanova, Gulhayo; Karputina, Margarita; Khargeliia (Karputina), Daria; Garcia, Jarem; Odyntsova, Vira; Martins, José Inácio Ferrão da Paiva
    For the first time, sucralose cathodic electrochemical determination, assisted by the safranin-modified electrode in acidic solutions, has been theoretically described. The correspondent mathematical model analysis has shown that the steady-state stability range is wider than in most systems of electrochemical determination over the pyridinic nitrogen-containing conducting polymer. Moreover, the oscillatory behavior is less probable than in similar systems in acidic media. Nevertheless, it is more probable than in neutral media. Nevertheless, poly(safranin) is an efficient electrode modifier for sucralose electrochemical determination.
  • Ескіз
    Документ
    The theoretical description for CoO(OH)-assisted salicylic acid derivatives determination in beer
    (2023) Tkach, Volodymyr; Morozova, Tetiana; Kushnir, Marta; Prymachenko, Serhii; Oliveira, Sílvio C.; Yuzkova, Valentyna; Nazymok, Yevgeniya; Banul, Bohdana; Honchar, Tetiana; Garcia, Jarem; Nikitchenko, Liliya; Yagodynets, Petro; Kormosh, Zholt; Palamarek, Karina; Chychun, Valentyna; Bagrii, Konon; Paiva Martins, Jose Inacio Ferrao; Khmeliar, Inesa; Kushnir, Lesya; Sabadyshyn, Rostyslav; Lysytsia, Dmytro; Sharipova, Riboba; Musayeva, Dilfuza; Lavrik, Ruslan; Moroz, Valerii; Hrabovska, Olena; Tkachenko, Lyubov; Khargeliia (Karputina), Daria; Karputina, Margarita; Grekova, Alla; Burdinina, Yanina
    In this work, the possibility of the electrochemical determination of salicylic acid on conducting polymer – CoO(OH) composite has been evaluated. The electrooxidation mechanism includes the gradual phenolization of the aromatic ring carbon atoms 3 and(or) 5 with further electrooxidation to the correspondent quinone. The analysis of the correspondent mathematical model utilizing linear stability theory and bifurcation analysis confirms the conducting polymer composite efficiency in salicylic acid determination in a wide concentration range. On the other hand, the oscillatory behavior in this system is possible, but its realization and feature strongly depend on the analyte nature and background electrolyte composition.