Extraction and spectrophotometric determination of nickel in coal fly ashes and stack gas using 2-[2-(3,5-dibromopyridyl)azo]-5-dimethylaminobenzoic acid

Abstract

2-[2-(3,5-Dibromopyridyl)azo]-5-dimethylaminobenzoic acid has been shown to form a stable blue complex with nickel(II) that can be extracted into chloroform. The reagent reacts with only a few metal ions. Interference from iron can be masked with Tiron and other interferents can be removed with EDTA. Microgram amounts of nickel in coal fly ash and stack gas have been determined satisfactorily.