The spectrophotometric determination of riboflavine in urine

Abstract

A simple spectrophotometric method for the determination of riboflavine in urine is described. The urine, after treatment with zinc acetate and formaldehyde, is passed through a small column of large particle-size talc on which the riboflavine is selectively and quantitatively adsorbed. Successive washings with 0·01 N hydrochloric acid and 5 per cent. dioxan remove the urinary pigments and other urinary constituents almost completely. The riboflavine eluted with 20 per cent. dioxan is measured spectrophotometrically at 444 nm. Some results are given for the rate of excretion of riboflavine in urine following intravenous injection of the vitamin.