Romanian Society of Pharmaceutical Sciences

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PHYSICO-CHEMICAL AND ELECTROANALYTICAL CHARACTERIZATION OF TWO ROMANIAN CLAYS WITH POSSIBLE APPLICATIONS IN PHARMACEUTICAL ANALYSIS

ADELA MAGHEAR1, CECILIA CRISTEA1,*, ANA MARIAN2, IULIU O. MARIAN2, ROBERT SĂNDULESCU1

1Iuliu Haţieganu University of Medicine and Pharmacy, Faculty of Pharmacy, Analytical Chemistry Department, 4 Pasteur St, 400349 Cluj-Napoca, Romania,
2Babeş-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos St, 400021, Cluj-Napoca, Romania

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The high demand for simple, fast, accurate, and sensitive detection methods in pharmaceutical analysis has driven the development of novel electrochemical sensors. Clay modified electrodes are likely to be used for this application. In this study, clays were used as electrode modifiers to improve the electrochemical properties of the existing electrodes. Bentonites obtained from Răzoare and Valea Chioarului deposits (Maramureş County, Romania) were refined and characterized by X-ray diffraction and transmission electron microscopy. The ion exchange capacity of purified clays was determined by replacing the compensatory ions with NH4 + ions. These clays were used to modify carbon paste electrodes (CPEs). The electrochemical behavior of acetaminophen, ascorbic acid, and riboflavin phosphate was tested by using cyclic voltammetry on clay-modified CPEs with different clay particle sizes. Resulting CPEs revealed either better electroanalytical signals or oxidation at lower potential. The development of new clay-modified sensors using such composite materials based on micro and nanoparticles could be applied in pharmaceutical analysis.