Determination of Pb2+ in natural waters with 2-mercaptobenzimidazole-5-sulfonate (MBIS) chemically modified gold electrode.
The preparation, characterization and analytical applications of gold electrodes modified with omega-mercapto alkyl/aryl sulfonates are described. The devices resulted effective for the determination of free and labile Pb(II) in water samples by anodic stripping voltammetry (E(dep) = -600 mV) and in particular 2-mercaptobenzimidazole-5-sulfonate (MBIS) offered the best performances with detection limit of 0.4 microg L(-1). Quantitative stripping of Pb from the electrode surface during the anodic scan, is obtained using sodium citrate buffer (pH = 9.0) as supporting electrolyte. Natural waters were analysed by standard addition method with good recoveries (mean percentage = 97%); no fouling effects due to humic acids or other organic constituents were observed in the reported conditions.
Zavarise
Francesca
F
Dipartimento di Chimica Generale, Università degli Studi di Pavia, 27100 Pavia, Italy.
Merli
Daniele
D
Profumo
Antonella
A