Fig. 1. SWASV responses of 50.0 g L−1 Cd(II) in hydrochloric acid solution (pH 2.0) at (a) Bi–SbFE, (b) SbFE, (c) BiFE and (d) GCE. (e) SWASV responses at Bi–SbFE in the absence of Cd(II). Deposition potential: −1.30 V; deposition time: 210 s; quiet time: 15 s; frequency: 25.0 Hz; pulse amplitude: 50.0 mV; scan increment: 4.0 mV.