3.4. Optimization
Firstly, the voltammetric responses of 2-TBI/GC electrode toward 0.25 nM of Cd(II) ion solutions were examined in different supporting electrolytes with different pH for 25 minute incubation. It was seen that the peak-current and the shape of voltammograms were the highest and the most suitable when experiments were performed in a sodium acetate/acetic acid solution of pH 5.0 (Fig. 8A). To find optimal incubation time, the 2-TBI/GC electrode was immersed in sodium acetate/acetic acid solution of pH 5.0 with 0.25 nM of Cd(II) ions for different periods (5, 15, 25, 35 and 45 min). It was observed that adsorptive stripping voltammograms increased hyperbolically and it reached a steady value if the incubation period passed 25 min (Fig. 8B).