Abstract
A colorimetric determination of orotic acid reported by Tsuji which consists of three steps, bromination of orotic acid, reduction by thioglycollate and condensation with p-dimethylaminobenzaldehyde to yield an orange color, was examined in detail and improved in several points. Ascorbic acid gave better results than thioglycollate in the step of reduction. Satisfactory results were obtained when the improved method was applied to several multivitamin preparations.
