Influence of Bitartrate Ion Concentration in the Copper Electrodeposition Onto a Polycrystalline Gold Electrode

In the present work, the influence of the concentration of bitartrate ions (HT) on the copper electrodeposition process was analyzed. The study was carried out from an aqueous solution containing 0.001 M of CuX (where X = (NO3–)2 ,(Cl–)2, SO42–) and x M KHT (where x = 0.005 M, 0.01 M, and 0.015 M). From voltammetric and chronoamperometric studies, the results indicate that copper electrodeposition is a diffusion-controlled process. The current density transients were well described through a kinetic mechanism involving capacitive and faradaic contributions. The diffusion coefficient values of Cu1+ and Cu2+ result to be similar at the different concentration values of potassium bitartrate used in this work. This work is licensed under a Creative Commons Attribution 4.0 International License

Palladium Electrodeposition Onto a Carbon Fiber Ultramicroelectrode

In the present work, it was conducted an electrochemical and kinetic study of Pd electrodeposition onto a 7 μm diameter CF (carbon fiber) ultramicroelectrode from an aqueous solution containing 1 mM of PdCl2 and 1 M NH4Cl as supporting electrolyte, at 25 °C and pH = 4.5. The voltammetric study suggests that at slow scan rates, radial diffusion is favored. The experimental current density transients obtained from the potentiostatic study were well predicted by an instantaneous nucleation and growth mathematical model, that considers the formation of separated hemispherical nuclei. The number of nuclei formed on the electrode surface is potential dependent, and increases as the applied potential diminishes

A Kinetic Study of Silver Electrodeposition Onto Pt Ultramicroelectrodes From Amoniacal Solutions

A kinetic study of the Ag electrodeposition onto Pt ultramicroelectrodes of 10, 15 and 25 µm of diameter from an aqueous solution containing AgNO3 1 mM + NH4NO3 0.1 M was conducted at overpotential conditions through potentiostatic studies. The analysis of the current density transients indicates the existence of two 2D nucleation and growth processes previous to the 3D nucleation and growth process. This work is licensed under a Creative Commons Attribution 4.0 International License

DEVELOPMENT OF A SECOND TYPE ELECTRODE BASED ON THE SILVER/SILVER IBUPROFENATE PAIR FOR IBUPROFEN QUANTIFICATION IN PHARMACEUTICAL SAMPLES

Ibuprofen is a widely used pharmaceutical because of its therapeutic properties; it is considered a safe medicament, thus it does not require medical prescription to be sold. However, in order to ensure consumer's health it is indispensable that the pharmaceutical industry relies on analytic methods for its quantification. Potentiometry has proven to be a successful technique using second type electrodes, which in agreement with Nernst's equation can detect anions activity. On consideration of this, this research work presents the development of a second type electrode based on the silver/silver ibuprofenate pair. This involved modifying a pure silver wire using a sodium ibuprofenate solution, to obtain the redox pair. The following analytic parameters were obtained with the aid of the modified electrode: a sensitivity of -0.049 V decade [ibuprofenate]-1, 8 µmol L-1 for the detection limit and a quantification limit of 1.2 µmol L-1. The repeatability value in terms of the relative standard deviation was 5.9%. After performing an interferences analysis using some ions and excipients, it was corroborated that there were none, thus allowing appropriate quantification on a real sample