Extraction and spectrophotometric determination of bismuth(III) with N-m-tolyl-p-chlorobenzohydroxamic acid and xylenol orange

Abstract

A solvent extraction and spectrophotometric method for the determination of microgram amounts of bismuth(III) is described. The bismuth(III) is extracted at pH 4.5 with N-m-tolyl-p-chlorobenzohydroxamic acid and forms a mixed complex with xylenol orange, which gives a red colour, λ_max. 530 nm and molar absorptivity 2.0 × 10⁴ l mol^–1 cm^–1. Bismuth has been determined in alloy and pharmaceutical samples.