Amperometric determination of thiourea in alkaline media on a copper oxide–copper electrode

Abstract

A copper oxide-copper electrode was tested in alkaline media for the anodic electrochemical detection of thiourea (TU). The correlation between the history of the electrode and potential range for optimum sensing of the particular susceptible species was analysed by electrochemical and surface layer techniques. The chemical composition and morphology of surface layers were examined using the SEM/EDX technique. Electrochemical data were obtained by cyclic voltammetry (CV) and chronoamperometry (CA). The linear calibration plots for an amperometric detection of TU in a delimited potential range, using CV and CA, were obtained for the 1-8 mM concentration range. Some considerations on the correlation between TU, electrode formation and polarization conditions are proposed. A copper oxide-copper electrode can be used as an inexpensive alternative for amperometric determination of TU in alkaline media without fouling the electrode surface.

Anodic Voltammetry of Thioacetamide and its Amperometric Determination in Aqueous Media

“…Thioacetamide (TAA), also known as thioacetimidic acid, or acetothioamide (CH 3 CSNH 2 ), is a widely used sulfur-containing compound both in the laboratory and in various technical applications [1][2][3][4][5][6][7][8][9][10] and can also be present in the environment as organic sulfur compounds [1,4,5]. TAA is used as a replacement for hydrogen sulfide in qualitative analyses and in hospital practice, as an accelerator in rubber vulcanization, as a reductant additive in the leather, textile and paper industries, generally having a similar role to thiourea [1][2][3].…”

“…TAA is used as a replacement for hydrogen sulfide in qualitative analyses and in hospital practice, as an accelerator in rubber vulcanization, as a reductant additive in the leather, textile and paper industries, generally having a similar role to thiourea [1][2][3]. The most important recent technical applications and research studies concerning TAA use now, also draw attention to the usefulness of TAA in the preparation of photocatalytic nanocomposites, mesoporous nanomaterials and metal chalcogenide thin films [6][7][8][9].…”

“…TAA hydrolysis [18][19][20], the use of TAA as precipitant reagent, as well as the various methods of quantitative determination by precipitation [21,22], amperometric or coulometric titration [23][24][25], redox reactions [26,27], potentiometry [28], utilization in precipitation and determination of various elements [29][30][31][32], anodization of mercury [33], cathodic stripping voltammetry [34,35], and even determination of TAA and a series of other thioamides by anodic voltammetry at solid metal electrodes [36,37], and associated problems concerning sulfide and H 2 S electrochemical oxidation or detection [38,39] have been experimented or applied. The common solid electrodes have rarely been tested for anodic determination of thioamides, with the exception of the application of pulsed amperometric detection (PAD) method [36] and new direct applications, such as determination of organic sulfur-containing compounds [3,40,41] and sulfide oxidation [38] at BDD, determination of thiourea at a BDD electrode [3] or thiourea at a copper oxide-copper electrode [2]. So, beside the classical precipitation or potentiometric methods, the electrochemical potentiodynamic variants, for example the use of mercury electrode and cathodic stripping voltammetry, cathodic stripping voltammetry at a silver electrode or pulsed amperometric detection at platinum or gold electrodes, are previous explored alternatives which involve several complications specific for metallic electrode in the presence of thioamidic compounds.…”

Electrochemical Determination of Diclofenac Sodium in Aqueous Solution on Cu‐Doped Zeolite‐Expanded Graphite‐Epoxy Electrode

“…By analogy with literature data [31,32] and based on the appearance of the second oxidation peak at higher potential value, the oxidation mechanism of diclofenac involving the redox couple Cu(III)/Cu(II) cannot be regarded as a simple mediated electrochemical process. The electrocatalytic activity of copper-based electrodes in alkaline media involves adsorbed hydroxyl radicals (HOC) ads.…”

CuO Crystalline Modified Glassy Carbon Electrodes for Anodic Amperometric Determination of Hydrogen Peroxide

“…6 For obtaining high current sensitivity of H 2 O 2 electrochemical sensing, noble metals have been widely used as the catalyst modifier for electrode fabrication, which involve platinum, 7 gold, 8 silver, 9 rhodium, 10 etc. Alternatively, for reducing the actual cost, metal oxides have also been intensively studied, involving iridium oxide, 11 iron oxide, 12,13 cobalt oxide, 14 manganese dioxide 15 and copper(II) oxide, [16][17][18][19] etc. The electrochemical deposition of nano-partiles on the electrode surface for fabrication of electrochemical sensors has shown advantages of simplicity and reliability.…”