No abstract

No abstract

No abstract

No abstract

Two methods for determining the ,itamin Dz content of oil solutions of irradiated ergosterol are described. In a spectrophotometric method the nonsaponifiable fraction of the oil is chromatographed, using a column of Superfiltrol and a solvent composed of a mixture of 30 parts of hexane, 10 parts of ether, and 1 part of alcohol. Interfering substances are adsorbed on the Superfiltrol while the vitamin D1 portion passes through the column.The vitamin Di content is evaluated by measuring its extinction at 263 mp. . i colorimetric method is proposed in which the nonsaponifiable fraction of .kRIOUS methods have been proposed for determining the vitamin D: content of irradiated provitamins D solutions and ah exten-ive review of these methods has been of fish liver oils. given ( 5 ) . Yield, Russell, and Zimmerli (7,12) found that by adding acetyl chloride to the antimony trichloride reagent of Brockmann and Chen ( 3 ) , its sensitivity could be increased and the presence of zinc, tin, or antimony had a tendency t o stabilize the color reaction. They also observed that sterols having double bonds in the side chain did not affect the reaction and those having double bonds in their ring structures gave the following absorption coefficients: El% 2 . 2 a t 500 mp El% 7 a t 515 i nM El% 1800 at 500 inlr 1 om.