The double deposition and stripping steps were proposed to increase the sensitivity in anodic stripping
voltammetry of lead and cadmium. Two in situ plated bismuth film electrodes at drastically different
surface areas were used for the measurements. Cadmium and lead were at first deposited atthe electrode
with a large surface area.When the deposition step atthe electrodewas finished,the electrodewas placed
at a short distance opposite the small one. Then Cd(II) and Pb(II) stripped from the first electrode were
deposited at the second electrode. Taking into account the small volume of space between the electrodes,
the concentration of Pb(II) and Cd(II) between the electrodes was drastically higher than that in the bulk
solution. The deposition step at the second electrode was performed from the solution with a higher
concentration of the determined ions, and so the detection limit was lowered. Calibration was performed
following deposition times of 300 and 120 s atthe first and the second electrode, respectively. Under such
conditions the detection limits of 1.8 × 10−10
and 4.5 × 10−11
mol L−1
for Pb(II) and Cd(II) were obtained,
respectively.