Spectrophotometric determination of thiambutosine

Abstract

N-(4-Butoxyphenyl)-N′-(4-dimethylaminophenyl)thiourea (thiambutosine) is made to react with 2,3-dichloro-1,4-naphthoquinone in an ethanolic medium and on rendering the reaction mixture alkaline with ethanolic ammonia solution a purple colour is developed with an absorption maximum at 540 nm. A procedure based on this reaction is described for the assay of thiambutosine in micro-amounts. The method is applied to its determination in tablets. The results are in agreement with those obtained by the official method.