Abstract
Purification methods of the reagents used in the Bessey method for vitamin A were improved and simplified. The optical density at 328mμ of kerosenexylene mixture alone was found to rise under the condition of photolysis which makes the correction due to the change in a blank test necessary to determine vitamin A. Under these conditions, vitamin A ester behaves similary to vitamin A alcohol, indicating practically complete saponification of the ester.
The values for human serum vitamin A determined by this method were in good agreement with those determined by a micro-GDH-method described in this paper.
Carotene is photolyzed under the condition but the effect is insignificant for vitamin A determination. The effect of carotene on GDH method is likewise insignificant usually.
