Elimination of intermetallic compound interferences in twin-electrode thin-layer anodic stripping voltammetry

Microelectrodes for the Determination of Heavy Metal Traces in Physiological Conditions. Hg, Cu and Zn Ions in Synthetic Saliva

“…The formation of the Cu-Zn intermetallic species, widely reported in the literature when using Hg electrodes [84,85], was not usually observed using graphite electrodes [86]. We believe that the amount of Hg present at the surface of microelectrodes from reduction of Hg analyte, which is actually very low in comparison to that of an Hg electrode, could be unable to promote the formation of Cu-Zn intermetallic compounds.…”

Study of the copper-zinc interference in potentiometric stripping analysis

“…Hence, with a hanging mercury drop electrode, interference was only observed when very concentrated solutions were electrolysed or when very long electrodeposition times were used.sl3 On the other hand, with mercury film electrodes interfering effects were always observed irrespective of the experimental conditions employed. [11][12][13][14][15][16][17][18] The effects observed included a decrease in the stripping wave of zinc as the copper concentration increased to give a signal that appeared at a potential very close to that for the stripping of copper. In an extreme situation, complete suppression of the zinc signal was observed if the concentration of copper was sufficiently high.…”

Stripping chronopotentiometry at scanned deposition potential (SSCP). Part 5. Features of multi-metal systems

“…1 and 2) much higher concentrations of Cu must be present before a significant impact on the Zn stripping peaks is observed ( Table 1). The Zn contained in solid CuZn intermetallic compounds has been reported to oxidise at potentials significantly more positive than that for soluble Zn amalgam [27,28]. Determination of the solubility product of the CuZn compound in Hg is dependent on the scan rate employed in stripping voltammetric measurements, with lower values being determined at higher scan rates [27].…”