Fig. 6. SWASV of different concentrations of Cd(ii) and Pb(ii) at the Bi/MWCNT–Nafion/GCE using double deposition and stripping steps. From bottom to top: 1, 5, 10, 15, 20, 25, 30, 35, 40 and 45 μg L−1. The right section of the figure shows the calibration curves for (A) Cd(ii) and (B) Pb(ii). First deposition step: deposition time: 700 s; deposition potential: −1.2 V; Bi(iii) concentration: 600 μg L−1. Second deposition step: deposition time: 280 s; deposition potential: −1.2 V.
