Abstract
The determination of vitamin D by USP XVI method has been studied. This method involves saponification, extraction, column partition chromatography, Fuller's earth adsorption chromatography, and correction colorimetrically by color inhibitor. Vitamin A can be separated from vitamin D by the partition chromatography, but vitamin A deconpositions can not be separated. This interfered substances can not be also separated throughly by the Fuller's earth chrometography. The correction factor of color inhibitor on the interfered substances are 0.26〜0.87 and not in accordance with 0.67 by USP.
