Chelatometric titration of bismuth with hedta

Talanta. 1985 Dec;32(12):1125-8. doi: 10.1016/0039-9140(85)80236-8.

Abstract

A new chelatometric method for the determination of Bi in bismuth-base alloys, low-melting alloys and reagent-grade bismuth salts is proposed. It is based on the chelation of Bi(III) with HEDTA, which is added in substoichiometric amount in perchloric acid medium to eliminate the interfering side-reactions of olation and oxolation, followed by pH adjustment and titration at pH 2 with Semi-Xylenol Orange as indicator. It is more selective than the classical EDTA method, and the accuracy and precision are enhanced. The coefficient of variation was found to be ~ 0.1%.