Abstract
Riboflavin determination was attempted with Farrand photoelectric fluorometer. The Fujita's lumiflavin method, benzyl alcohol method and Crammer-Yagi's method were satisfactorily applied to this apparatus. One ml. of blood was sufficient for measurement of both free and esterified form of riboflavin. The riboflavin level of various bodily parts of normal albino rats estimated with this apparatus corresponded with that was confirmed by other authors.