Байланысты: Сборник конф Фараби Әлемі 2023 химфак-печать
DETERMINATION OF ASCORBIC ACID BY ELECTROCHEMICAL SENSORS BASED ON MOLYBDENUM OXIDE Assyr G.B., Sibay D.A. Scientific supervisors: Yeszhanova A.A., Zhumasheva N.Zh. Nazarbayev Intellectual School of Physics and Mathematics in Taldykorgan yeszhanova_a@tk.nis.edu.kz Relevance of the study: Molybdenum is in demand in the field of sensors due to its unique
physicochemical properties. In general, we can learn that molybdenum metal has a very wide range
of applications, as a cathode material in a chemical current source, as well as in increasing wear
resistance, protection from corrosion. Ascorbic acid, which is the main object of research, is an
antioxidant of immunomodulatory anti-inflammatory action, having a pleiotropic effect. But due to
the fact that ascorbic acid is not synthesized in the human body, it becomes necessary to conduct an
analytical analysis to determine its amount.
The aim of the study:
To determine the sensitivity of a glass carbon electrode modified with
molybdenum oxide to ascorbic acid of various concentrations.
Research methodology: collection of information in the literature, construction of graphs and tables.
Conducting research using cyclic voltammetry and quad-wave voltammetry using the AUTOLAB
electrochemical system. The glass carbon electrode was modified with molybdenum oxide for the
first time and was used to determine various concentrations of vitamin C.
Results and their discussion: The sensitivity of the electrode modified with molybdenum
oxide was tested under different conditions and comparisons were made with the electrode not
fitted with molybdenum oxide. First, an analysis of the sensitivity of the electrode with
molybdenum oxide to different amounts of Vitamin C was carried out. A second CV test was
performed to see if the sensitivity of the modified electrode surface increased. The sensitivity of the
electrochemical sensors was measured using Ferri/Ferrum cyanide probe at KCl. for Ferri / Ferrum
cyanide glasscarbon, the current density is located low, respectively, the sensitivity is also reduced.
The electrode surface sensitivity is increased. And in the third test, we determined the sensitivity of
the electrode, increasing the concentration of vitamin C by 1 ml. Therefore we can conclude that the
concentration is directly proportional to the current density.
Сonclusion: Electrochemically, molybdenum oxide was deposited on the surface of the
glass carbon electrode at pH=3 against the background of an acetate buffer from a sodium
molybdate salt solution.By the method of SWV-square-wave voltamperometry, a glass carbon
electrode transformed by molybdenum oxide was studied and determined to be sensitive to ascorbic
acid. The sensitivity of a glass fiber electrode modified with molybdenum oxide to ascorbic acid of
various concentrations was determined.