Electrochemical and quartz crystal microbalance studies of lead(II) deposition and stripping in the presence of copper on a gold electrode modified with 2,2′-bipyridyl in polyaniline

Abstract

Electrochemical and quartz crystal microbalance (QCM) measurements were used to determine the mechanisms of anodic stripping voltammetry (ASV) processes during lead determination in samples containing copper on a solid electrode modified by 2,2′-bipyridyl (Bpy) in polyaniline (PANI). Deposition of lead and copper results in the formation of solid solutions, which may change the results. An improvement of lead determination was achieved by the formation of stable copper complexes with Bpy. The molecules of Bpy were immobilized on a solid electrode in a PANI film. Deposition and stripping of lead and lead with copper were compared on three different electrodes: gold, gold coated with PANI and gold coated with PANI modified by Bpy. The results were used to propose mechanisms of deposition and stripping processes as well as a practical procedure of using this kind of electrode.