Electroanalytical Properties of a Thin-Film Mercury–Carbon Electrode of Subnanometric Thickness in High-Speed Linear-Sweep Anodic Stripping Voltammetry as Exemplified by the Determination of Zn(II), Cd(II), and Pb(II)

A mercury–carbon electrode formed in situ on a carbon fiber support (at a mercury film thickness of 0.33 nm and a polarization potential sweep rate of 100–1000 V/s) exhibited properties typical of an indifferent solid electrode. They specifically affect the detected analytical signals of metals soluble in mercury (Zn, Cd, and Pb). The value of this signal depends on both the analyte concentration in solution and the concentrations of other metals that can be electrolytically accumulated in a thin mercury film. Based on this property, one can determine nanomolar concentrations of the above metals with electrolytic accumulation for 20–200 s.