Selective microdetermination of antimony(III) with a pyrimidyl azo dye, 2,4,6-tris(1-hydroxy-4-sulphonaphthyl- 2-azo )pyrimidine

Abstract

Sodium salt of 2,4,6-tris(1-hydroxy-4-sulphonaphthyl- 2-azo )pyrimidine reacts with antimony(III) at <i>p</i>H 4.5-6.0 to form a violet coloured 1:1 complex with absorption maximumat 560nm. The molar absorptivity of the complex is 3.4 x 10⁴ 1 mol^{- 1} cm^{- 1}. The method based on this complexation reaction is highly selective for the estimation of antimony(III) in the presence of 1.10-phenanthroline. It has been used for the determination of antimony (III) in synthetic solutions corresponding to some important alloys.