Vitamin methods

The metabolism of niacytin in the rat. Studies of the excretion of nicotinic acid metabolites

“…Nicotinic acid was determined by the method of Wang & Kodicek (1943). The E457 ofthe final solution was determined in 4cm x 1 cm cells, and allowance was made for fading of the colour.…”

“…Tertiary nicotinoyl derivatives were extracted from urine with alkali by the method of Wang & Kodicek (1943) as follows. A 5ml volume of lOM-NaOH was added to 50ml of urine, and the mixture was digested at 1000C for 45min, cooled, 30 ml of water added, the pH adjusted to 2.6 and the volume was made up to lOOml.…”

The fluorimetric estimation of nicotinamide in biological materials

“…These break down during the pre-treatment and nicotinamide is liberated. Precautions must be taken which have been already described by Wang & Kodicek (1943) in the CNBr reaction: the pH must be adjusted carefully to 7-2, and only fresh cyanogen bromide, prepared from ice-cold solution, should be used.…”

EFFECT OF ACETOACETATE AND Β-Hydroxy-Butyrate ON THE BIOSYNTHESIS OF NIACIN FROM TRYPTOPHAN

“…Urinary niacin was determined by the method of Swaminathan (10) and the total niacin content of blood and tissues by the method of Wang and Kodicek (11).…”