[An automated photometric method for determining niacin and niacinamide content in grain and cereals].

The subject of this report is an automated photometric method for the determination of the content of total niacin in grain and cereal food. The customary coupling reagent sulfanilic acid has been replaced by 1,3-dimethylbarbituric acid; CNCl is produced in the flow through system directly from KCN and chloramine T. The composition of reagents, the procedure and the analytical manifold are specified. 30 analyses/h can be performed. The accuracy and reproducibility of the automated method is good. In a range of 0.5-4.0 micrograms/ml niacin and a total content of 10-135 mg niacin/kg dry matter an average variation coefficient of vk = 0.74% (n = 10) was obtained. When lack of homogeneity of samples and variation in alkaline hydrolysis are included average vk to +/- 2.43% at the same range of niacin. The content of total niacin in various kinds of grain and in enriched ready to eat cereal foods was determined.