Highly Sensitive and Selective Measurement of Bismuth in Seawater and Drug with 1,2-Phenylenedioxydiacetic Acid by Cathodic Adsorptive Stripping Voltammetry

A new method is presented for determination of bismuth based on cathodic adsorptive stripping of complex bismuth with 1,2‐phenylenedioxydiacetic acid (PDA) at a hanging mercury drop electrode (HMDE). The effect of various parameters such as pH, concentration of ligand, accumulation potential and accumulation time on the selectivity and sensitivity were studied. The optimum conditions for determination of bismuth include nitric acid concentration 0.01 M, 8.0×10−4 M PDA and accumulation time 120 s, accumulation potential of −200 mV. The limits of detection are 0.25 and 0.05 nM, and responses are linear 1–1000 and 0.1–400 nM at tacc of 60 and 120 s, respectively. Many common anions and cations do not interfere in the determination of bismuth. The method was applied to the determination of bismuth in some real samples such as sea – and spring water and drug.