[Determining riboflavin level in urine (comparative analysis of the methods)].

Four methods of riboflavin content estimation in urine were studied: they are based on specific titration of vitamin B by riboflavin-binding protein (1), riboflavin decomposition by boiling in alkali (2), riboflavin fluorescence suppression by dithionate (3), and high-performance liquid chromatography. A conclusion has been made on the necessity of a home standard for riboflavin estimation by methods 1-3. The results obtained with the above methods correlated well, regression equations were derived describing correlation of these results. Methods 1 and 3 are most simple and highly specific and sensitive, therefore they could be recommended for wide use in large-scale clinical investigations.