Voltammetry of Organic Microparticles

Abstract

Solid microparticles of several different insoluble organic compounds were mechanically immobilized on the surface of graphite electrodes and immersed into a liquid electrolyte in order to study their electrochemical reactions. Cyclic staircase voltammetry and square-wave voltammetry were used. Quinhydrone was found to be a stable intermediate in the reversible redox reaction of solid quinone and hydroquinone on the electrode surface. The reaction occurs on the surface of the solid particle which is in contact with water. Indigo can be reduced to leucoindigo and oxidized to dehydroindigo in two separate reversible redox reactions. In strongly basic medium indigo dissolves in water upon electroreduction. A hydroacridine radical was detected as a stable intermediate in the electrochemically irreversible redox reaction of acridine and dihydroacridine. Famotidine can be electrooxidized and the product of this reaction can be electroreduced in two separate chemically irreversible reactions. Probucol is oxidized to a semiquinone radical which can be re-reduced in an electrochemically irreversible redox reaction. Propylthiouracil can be also oxidized to an unknown product which can be re-reduced in a chemically reversible, but slow solid state surface redox reaction. Reductions of solid thionicotinoylanilide and nicotinoylanilide are totally irreversible.

Electroanalytical Study of the Composition of the Raw Pigment Mixtures that Yield the Metallic Lustre on Ceramics. A Link Between Composition and Final Result

“…It can be applied to a broad set of materials from organic [8] to inorganic samples [9] and it provides information about the chemical and physical composition of the sample. It also has been used to study chemical or electrochemical processes [10].…”

Solid State Electrochemical Oxidation Mechanisms Of Morin in Aqueous Media

“…Similarly, there is good agreement between redox cycling of MnO 2 using VMP and the compact-electrode method [14], but the VMP measurement is ten to a hundred times faster. In the voltammetry of organic microparticles, redox reactions can be either destructive, i.e., leading to a dissolution of the particle, or not, depending on the solubility of the reaction products [15]. The heterogeneous charge transfer reaction occurs at the three-phase boundary, at which the electrode, the particle and the electrolyte are in contact [16 -18].…”

Electrochemical Response of Acridine Orange in Bacterial Cell

“…4. [24][25][26][27] The oxidation peak at 0.72 V was attributed to the oxidization of neutral AO to the radical cation form (AO +• ) in Fig. 4a.…”