Simultaneous Determination of Cr(III) and Cr(VI) by Differential Pulse Voltammetry Using Modified Screen‐Printed Carbon Electrodes in Array Mode

Abstract

A new procedure for the speciation of chromium by means of differential pulse voltammetry using screen-printed carbon electrodes (SPCEs) has been proposed. Two different modified carbon working, a Ag/AgCl reference and a carbon counter screen-printed electrodes have been connected in array mode for the simultaneous determination of Cr(III) and Cr(VI). Mercury films or gold nanoparticles have been ground onto the SPCEs in order to improve their selectivity to each chromium species. The quantification of the peak currents observed at À1.25 V in Hg-SPCE and À0.1 V in AuNPs-SPCE were carried out. The method has been applied to the speciation of chromium in waste water from a tannery factory.

Electrochemical speciation analysis for simultaneous determination of Cr(iii) and Cr(vi) using an activated glassy carbon electrode

“…S1A2 and B2 † prove that the higher temperature of the solution enhances the electrochemical signal of Cr(III) and Cr(VI). Moreover, the electrochemical signals of Cr(III) and Cr(VI) strongly depend on the pH value, 32,42 which is proven in Fig. 1A1 and B1.…”

“…36 The second method is the speciation analysis of Cr(III) and Cr(VI) using different solutions 2 or using different modified electrodes. 42 The last method is the simultaneous speciation analysis of Cr(III) and Cr(VI) in the same electrochemical system (the same buffer and the same working electrode). 39,40 The last method of determination of the total Cr presents some advantages compared to the others.…”

Extraction Induced by Microemulsion Breaking and Square Wave Voltammetry: A Promising Union to Monitor Cd, Pb and Cu in Biodiesel

“…17 Moreover, metals could be present in vegetable oils coming from seeds, due to the availability of metals in the soil from pesticides and fertilizers. 58,59 The metals cited above as well as other elements like Zn II , V V , Mo VI , Ti IV , Te IV , Sn IV , In II , As III , U VI and Se IV can be determined using the HgGCE as WE, 29,[60][61][62][63][64][65][66][67][68][69][70][71][72] although for many of them the determination is only possible in the presence of specific ligands and after applying adsorptive stripping voltammetry with a cathodic potential sweep. It is, therefore, important to assess the possible interference caused by them on the voltammograms of Cd, Pb and Cu since they could interact with the Hg film and appear in the potential window during the stripping step.…”

Carbon Nanotube–Based Electrodes for Detection of Low–ppb Level Hexavalent Chromium Using Amperometry

“…12 However, commercial carbon SPEs can be easily modified with surface chemistry or nanoparticles to improve the sensitivity or selectivity. For example, SPEs have been modified with L-3,4-dihydroxyphenylalanine (L-DOPA), 13 as well as with Au and Ag nanoparticles [14][15][16] for Cr(VI) detection. Although the unique optical properties of carbon nanotubes (CNTs) have made them excellent fluorescence sensors for a variety of applications, 17,18 electrodes based on carbon nanotubes (CNTs) have also been useful for electrochemical sensors.…”