Determination of cadmium(II) by square wave anodic stripping voltammetry using bismuth–antimony film electrode

In this work, a bismuth–antimony film electrode (Bi–SbFE) is reported for the first time as a possible alternative for electrochemical stripping analysis of trace heavy metals. The Bi–SbFE was prepared in situ on a glassy carbon electrode and employed in combination with square wave anodic stripping voltammetry in hydrochloric acid solution (pH 2.0). Several key operational parameters influencing the electroanalytical response of Bi–SbFE were optimized, such as the different proportions of Sb(III) and Bi(III), pH value of the measure solution, deposition potential and deposition time. Compared with the bismuth-film electrode (BiFE) and antimony-film electrode (SbFE), the Bi–SbFE displayed higher stripping current response. Under the optimum conditions, the sensor revealed highly linear behavior in the examined concentration range from 1.0 to 220.0 μg L−1, with the detection limit of 0.15 μg L−1 for Cd(II), offering good reproducibility. The method was applied to the analysis of Cd(II) in tap water sample with satisfactory results.