Simultaneous determination of bismuth and lead by single-sweep polarography of their glyoxalbis(2-hydroxyanil) complexes

Abstract

Bismuth(III) and lead(II) can be reduced at –0.65 V (versus SCE) and –0.76 V (versus SCE), respectively, in a sodium hydroxide solution containing glyoxalbis(2-hydroxyanil)(GBHA)[2,2′-(ethanediylidenedinitrilo)diphenol] by using single-sweep polarography, based on their adsorptive GBHA complexes. Both waves are sensitive and selective and can be utilised for the simultaneous determination of these two elements. The linearity ranges for bismuth and lead are 7 × 10^–8–1 × 10^–5 and 1 × 10^–7–6 × 10^–6M, respectively. The sensitivity for bismuth can be increased ten-fold by using cathodic stripping voltammetry with a static mercury electrode. The proposed procedure was applied to the simultaneous determination of bismuth and lead in some ore and alloy samples. The mechanism of the electrode process has also been studied.