摘要：Colorimetric determination of phenacetine in mixed pharmaceutical preparations was examined and a new method with high accuracy and selectivity was established. Phenacetine was hydrolysed by refluxing with hydrochloric acid to produce p-phenetidine which reacts with sodium nitrate in an acid medium to from diazonium compound. Coupling of the resulting diazonium compound with β-diethylaminoethyl-α-naphthylamine oxalate produced blue dye. The diazo dye had an absorption maximum at 595 mμ. Interference by the presence of acetaminophen, nicotinoyl-4-aminoantipyrine, antipyrine, and aminopyrine can be eliminate by chloro- form extraction in acid medium.
