Shanghai Research Institute of Materials, The Ministry of Machine Building Industry, Shanghai, People's Republic of China
The Third Factory of Shanghai Reagent Chemicals, Shanghai, People's Republic of China
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%.