Square-wave voltammetric stripping analysis of bismuth(III) at a poly(4-vinylpyridine)/mercury film electrode

A novel poly(4-vinylpyridine)/mercury film electrode (PVP/MFE) was developed for the determination of trace Bi(III) in real samples by square-wave anodic stripping voltammetry (SWASV). The preconcentration of the anionic forms of Bi(III) from chloride medium onto the modified electrode is based on the ion-exchange effect of the PVP. The good solubility of bismuth in mercury also helps to increase the preconcentration effect. Various factors influencing the determination of Bi(III) were thoroughly investigated. In comparison with the conventional MFE, this modified electrode showed improved resistance to interferences from surface-active compounds and common ions, increased sensitivity when used in conjunction with SWASV and better mechanical stability of the mercury film. In addition, detection can be achieved without deoxygenation and the electrode can be easily renewed. The analytical usefulness of the PVP/MFE is demonstrated by application to various water samples.