Title: Determination of Kjeldahl Nitrogen in Foodstuffs as Indophenol
Abstract: The indophenol method for determining Kjeldahl nitrogen has been studied and has been applied to the analysis of foodstuffs. A photometric determination of ammonia is based on the reaction with phenol and hypochlorite, to give an indophenol which is intensively blue in an alkaline medium. The procedure is better in reproducibility than previously reported methods. The indophenol method may be considered a general method for the determination of Kjeldahl Nitorogen in foodstuffs. The results obtained from the analysis of certain foodstuffs and organic compounds by the indophenol method are compared with those obtained by the semimicro-Kjeldahl method.