A study of the preconcentration and stripping voltammetry of Pb(ii) at carbon electrodes

Abstract

Both glassy carbon electrodes and carbon fibre microelectrodes were shown to accumulate Pb 2+ ions at open circuit, the amount of Pb 2+ accumulated being determined by anodic stripping voltammetry in 0.1 M HCl following the accumulation step. The mechanism of Pb 2+ accumulation was investigated by studying the effects of the pH of the solution, the concentration of Pb 2+ and the preconcentration time on the amount of Pb 2+ accumulated. For a 5 min preconcentration time at open circuit, using a glassy carbon electrode (4 mm diameter) and a carbon fibre microelectrode (8 mm diameter), detection of around 10 nM Pb 2+ was obtained for both electrodes. The pH dependence of the amount of Pb 2+ accumulated suggests that the Pb 2+ ions are complexed by carboxylate groups at the surface of the carbon electrodes. This conclusion is supported by results obtained using basal plane and edge plane pyrolytic graphite electrodes and by studies of the effects of electrochemical oxidation of the glassy carbon surface on the magnitude of the lead stripping peak.

Electrochemical Investigation of Cysteamine at Carbon Fiber Microdisk Electrode

“…Pt, Au, Hg and carbon microelectrodes have been used in stripping analyses for the determination of trace metals by a number of authors. [4][5][6][7][8] In contrast, studies using microelectrodes for the determination of organic species are far less numerous and are restricted to the use of carbon fiber microelectrodes.…”

Effect of the sp2/sp3 Ratio in a Hybrid Nanocarbon Thin Film Electrode for Anodic Stripping Voltammetry Fabricated by Unbalanced Magnetron Sputtering Equipment

“…34,46,47 This is because an edge plane contributes more to the reduction of the target metals than a basal plane in ASV measurements. 48 The electron transfer rate constant (k0) on UBM (50:50) was about 4.5-times smaller than that of UBM (80:20) (Table 3). This implies that the content of the edge plane in a UBM electrode becomes smaller as the sp3 content increases.…”

New Pb2+ carbon paste electrode based on organically modified silicate and its square wave anodic stripping voltammetric response for pretreated gasoline samples

“…26 In Figure 4, the effect of varying deposition time on anodic peak current using the APSil modified carbon paste electrode is shown for an aqueous solution containing…”