scholarly journals On the Mechanism of the Reduction Process of the Hydrogen Ion at the Dropping Mercury Electrode. I. Theoretical Part

1952 ◽  
Vol 25 (5) ◽  
pp. 287-293 ◽  
Author(s):  
Reita Tamamushi
1994 ◽  
Vol 77 (3) ◽  
pp. 768-773 ◽  
Author(s):  
Juan A Squella ◽  
Juan C Sturm ◽  
Alejandro Alvarez-Lueje ◽  
Luis J Núñez-Vergara

Abstract Electrochemical reduction of zopiclone at different pHs and concentrations was studied by polarography and cyclic voltametry. Both techniques revealed a reduction process with weak adsorption of both zopiclone and its reduction derivative. Zopiclone exhibited 2 differential pulse polarographic peaks at the dropping mercury electrode. The first peak was used to develop a differential pulse polarographic analytical procedure for determining the drug in pharmaceutical dosage forms. Reproducibility and recovery coefficients of variation were 1.6 and 2.2%, respectively. Analysis of commercial zopiclone tablets showed uniformity in zopiclone content. The method is simple and rapid because separation of excipients is unnecessary.


Electrochem ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 415-426
Author(s):  
Juan Torrent-Burgués

The effect of the adsorption of tetraethylammonium (TEA) cations, which present both ionic and organic characteristics, on the reduction of Cd(II) ions have been studied from dc and ac measurements at the dropping mercury electrode. The resistance to the charge transfer (Rct) and Warburg coefficient (σ) parameters have been determined through impedance measurements. Thus, the global velocity constant has been obtained. The reduction process of Cd(II) in perchloric media is reversible and is affected by the adsorption of TEA cations, especially at high TEA concentrations. Values of E1/2, half wave potential, and DO, diffusion coefficient, obtained from both dc and ac measurements agree. The velocity constants show a decrease as TEA concentration increases, with values ranging from 0.6 to 0.01 cm·s−1. The inhibitory effect of TEA adsorption on the electrode process and the relationship between electrode coverage, θ, and velocity constants, K, using several isotherm equations, have been discussed. The best fit was obtained with the equation K = 0K(1 − θ)a with an a value close to three, indicating a blocking effect and electrostatic repulsion due to TEA.


1987 ◽  
Vol 52 (11) ◽  
pp. 2810-2818 ◽  
Author(s):  
Emil Paleček ◽  
František Jelen ◽  
Vladimír Vetterl

The behaviour of electrochemically reducible single-strand polynucleotides (poly(adenylic acid)) and poly(cytidylic acid)) was studied by the differential (derivative) pulse polarography (DPP) and by other methods. Measurements were performed with the help of the dropping mercury electrode under various conditions specified by the pulse width, pulse amplitude, drop time etc. For the faradaic and tensammetric DPP peaks the diagnostic criteria were proposed which make it possible to classify even very small DPP peaks of double helical polynucleotides.


1983 ◽  
Vol 48 (10) ◽  
pp. 2903-2908 ◽  
Author(s):  
Viktor Vrabec ◽  
Oldřich Vrána ◽  
Vladimír Kleinwächter

A method is described for determining total platinum content in urine, blood plasma and tissues of patients or experimental animals receiving cis-dichlorodiamineplatinum(II). The method is based on drying and combustion of the biological material in a muffle furnace. The product of the combustion is dissolved successively in aqua regia, hydrochloric acid and ethylenediamine. The resulting platinum-ethylenediamine complex yields a catalytic current at a dropping mercury electrode allowing to determine platinum by differential pulse polarography. Platinum levels of c. 50-1 000 ng per ml of the biological fluid or per 0.5 g of a tissue can readily be analyzed with a linear calibration.


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