Preparation and Properties of Mercury Film Electrodes on Solid Amalgam Surface

A simple apparatus (electrolyzer) and a reliable procedure were developed for the preparation of mercury films of exactly defined thickness on a silver solid amalgam substrate. Constant concentration of Hg(II) in the electrolyzer is ensured by dissolution of an anode from silver paste amalgam. Small volume of electrolyte, which can be used repeatedly many times, and paste amalgam preventing the spillage of liquid mercury substantially decrease the danger of environmental contamination with mercury. Parameters and behavior of mercury film electrodes on silver solid amalgam substrate (MF-AgSAE) were compared with polished silver solid amalgam electrode (p-AgSAE) which does not contain liquid mercury, with mercury meniscus modified silver solid amalgam electrode (m-AgSAE), and with hanging mercury drop electrode (HMDE). The height of anodic stripping voltammetric peaks divided by electrode area was highest for MF-AgSAE and the width of those peaks, which determines the resolution of the method, was minimal at MF-AgSAE. Available potential window of MF-AgSAE in different supporting electrolytes is comparable with that of HMDE.