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G. K. Ziyatdinova A. A. Gainetdinova G. K. Budnikov 《Journal of Analytical Chemistry》2010,65(9):929-934
Synthetic phenolic compounds (pyrogallol, catechol, hydroquinone, and their derivatives bearing heterocyclic fragments) react
with electrogenerated titrants, halogens, and ferricyanide(III) ions. Stoichiometric coefficients of reactions are found.
It is shown that the use of ferricyanide(III) ions as a titrant and a one-electron oxidant for the determination of this class
of antioxidants offers advantages in comparison with titrants-halogens. The found amounts of pyrogallol, pyrocatechol, and
hydroquinone derivatives in model solutions with the RSD 1–5% are fractions of milligrams. It is found that, in the series
of the studied synthetic phenolic compounds, pyrocatechol derivatives possess the maximum antioxidant capacity (AOC). 相似文献
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Guzel Ziyatdinova Aliya Gainetdinova Mikhail Morozov Herman Budnikov Svetlana Grazhulene Arkady Red’kin 《Journal of Solid State Electrochemistry》2012,16(1):127-134
Glassy carbon electrodes (GCE) modified with carbon nanotubes (CNT) have been created for detection of phenolic compounds—one
of the important group of antioxidants in life sciences. The surface of electrode has been characterized by atomic force microscopy.
The presence of CNT leads to an at least 20-fold increase in the surface roughness of the electrode. The CNT layer displays
closely intertwined vermicular structures with high degree of homogeneity at CNT suspension concentration of 0.2–0.5 mg L−1. Synthetic water-soluble antioxidants (hydroquinone, catechol, pyrogallol, and their derivatives) are electrochemically active
on bare GCE and CNT-modified GCE in phosphate buffer solution pH 7.4. Effect of substitutes in molecular structure of phenolic
antioxidants has been evaluated. In several cases, oxidation at CNT-modified GCE occurs at potentials that are less positive
by 100–200 mV in comparison to bare GCE. The electrodes were studied with respect to their capability of phenols voltammetric
sensing. CNT-modified GCE display an enlarged linear range in the calibration graphs and lower detection limits. Voltammetric
method for determination of hydroquinone, catechol, pyrogallol, and their derivatives has been developed. 相似文献
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Nail H. Ibragimov Aliya A. Gainetdinova 《Journal of Applied Analysis & Computation》2017,7(3):872-883
Dynamical systems attract much attention due to their wide applications. Many significant results have been obtained in this field from various points of view. The present paper is devoted to an algebraic method of integration of three-dimensional nonlinear time dependent dynamical systems admitting nonlinear superposition with four-dimensional Vessiot-Guldberg-Lie algebras $L_4.$ The invariance of the relation between a dynamical system admitting nonlinear superposition and its Vessiot-Guldberg-Lie algebra is the core of the integration method. It allows to simplify the dynamical systems in question by reducing them to \textit{standard forms}. We reduce the three-dimensional dynamical systems with four-dimensional
Vessiot-Guldberg-Lie algebras to 98 standard types and show that 86 of them are integrable by quadratures. 相似文献
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