Analysis of Solutions Containing Two Reducible Substances by Polarography and Coulometry at Controlled Potential

Louis Meites

doi:10.1021/ac60103a020

Nuclear fuel technology - Controlled-potential coulometric assay of plutonium

10.3403/30381411u ◽

2019 ◽

Keyword(s):

Nuclear Fuel ◽

Controlled Potential ◽

Fuel Technology

Download Full-text

AFM and SEM Characterization of Chemically Modified Electrodes Based on 5-[(azulen-1-yl) methylene]-2-thioxothiazolidin-4-one

Revista de Chimie ◽

10.37358/rc.17.12.5981 ◽

2018 ◽

Vol 68 (12) ◽

pp. 2799-2803

Author(s):

Maria Daniela Pop ◽

Oana Brincoveanu ◽

Mihaela Cristea ◽

George Octavian Buica ◽

Marius Enachescu ◽

...

Keyword(s):

Glassy Carbon ◽

Roughness Parameter ◽

Modified Electrodes ◽

Chemically Modified Electrodes ◽

Adhesion Properties ◽

Chemically Modified ◽

Controlled Potential ◽

Constant Potential ◽

Metal Ions Detection

Preparation and microscopy characterization of polymer modified glassy carbon electrodes based on (5-[(azulen-1-yl) methylene]-2-thioxothiazolidin-4-one (L) were reported. Atomic Force Microscopy was used to investigate the morphological and mechanical properties of the deposited polyL films onto glassy carbon. The topography images of the analyzed samples exhibited the presence of some columnar shape features onto the layer surfaces. The surface roughness of the layers deposited at constant charge calculated from topography images, increased with the more positive applied potential for controlled potential electrolysis. At different charges, the roughness parameter showed the same behavior for the layers obtained applying a constant potential without having a noticeable influence on the adhesion properties on the substrate. Analysis using scanning electron microscopy shows a relatively uniform surface arrangement of the polymer and the presence of some clusters which are disturbing the planarity. PolyL chemically modified electrodes have been used for heavy metal ions detection with best results for lead.

Download Full-text

Electrolytic reduction of o-nitrobenzyl thiocyanate in buffered solutions on mercury

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19850033 ◽

1985 ◽

Vol 50 (1) ◽

pp. 33-41 ◽

Cited By ~ 4

Author(s):

Jaromír Hlavatý

Keyword(s):

Acidic Medium ◽

Reaction Path ◽

Electrolytic Reduction ◽

Buffer System ◽

Height Ratio ◽

Preparative Electrolysis ◽

Clear Explanation ◽

Ec Mechanism ◽

Controlled Potential

The o-nitrobenzyl thiocyanate (I) behaves differently on the DME and on a large mercury pool electrode. Polarography did not give a sufficiently clear explanation of the reaction mechanism, only the preparative experiments yielded useful results. Whereas polarographic curves in solutions of Britton-Robinson buffer system with 50% by vol. ethanol exhibit two cathodic waves within the pH region 1-12, corresponding according to their height ratio to an uptake of 4 e and 2 e respectively, the controlled potential preparation electrolysis (CPE) and coulometry results indicate a more complicated reaction path. In the CPE carried out at the concentration of I 1 . 10 -2 mol/l the electroreductive splitting of CH2-SCN occurs as the first step. Nitrobenzyl radicals so formed react in the follow-up dimerization resulting in dibenzyl or toluene structures. Simultaneously or at a later stage the completion of the electrolytic reduction of the nitro group proceeds to the hydroxylamino group. In solution of 9 > pH > 1 the CPE of nitro compound I takes place by an ECEC mechanism yielding dibenzodiazocine III, its N-oxide IV and 2,2'-dimethylazoxybenzene (V). In course of preparative electrolysis in strongly acidic medium 2-amino-benzo(l,3)-thiazine-l-oxide (II) is formed by an EC mechanism.

Download Full-text