Rapid determination of primary amides

Abstract

A method for the determination of primary amides is presented that involves treatment with excess of nitrous acid-sulphuric acid at 0–5 °C. Unreacted nitrite is measured spectrophotometrically by a diazo-coupling reaction after passage through a copper-coated cadmium reducing column in order to reduce any nitrate ions produced by disproportionation of nitrous acid and by aerial oxidation of nitrogen oxide liberated during diazotisation of the amide. The technique can be used to determine 1.5 and 0.015 mg of amide nitrogen with relative standard deviations of 1.4 and 4.2%, respectively.