Spectrophotometric determination of 4-acetylaminobenzaldehyde thiosemicarbazone (thiacetazone) with 2,3-dichloro-1,4-naphthoquinone

Abstract

4-Acetylaminobenzaldehyde thiosemicarbazone (thiacetazone) is made to react with 2,3-dichloro-1,4-naphthoquinone in an ethanolic medium. When the mixture is rendered alkaline with ammonia a purple product with an absorption maximum at 560 nm is obtained. A method based on this reaction is described for the quantitative determination of micro-scale amounts of thiacetazone. The procedure is applied to its determination in tablets. The results are compared with those obtained by the official method.