抄録
It was found to permit a distinct separation of vitamin D from vitamin A alcohol by gel filtration utilizing Sephadex LH-20 as bed and chloroform as eluting solvent. But when applied to mixtures of vitamins A alcohol and D in the ratios usually found in pharmaceutical dosage forms, it was not possible entirely to eliminate interfering vitamin A degradation products which moved at the same rate as vitamin D. Effective removal of this interfering substances was achieved with Florex XXS column chromatography described by Schmall^<7)> with a slight modification. Taking these findings into consideration, a method for the determination of vitamin D in the presence of vitamin A involving gel filtration is proposed : After the gel filtration on Sephadex LH-20 column for removal of vitamin A alcohol from vitamin D, a persistent interfering band accompanying vitamin D is eliminated subsequently by means of weakened Florex XXS column containing 7% of water. Vitamin D is determined by applying Wilkie's color inhibitor and method of calculation and Nield's antimony trichloride reagent. Satisfactory recovery was shown in the experiments of mixtures of vitamins A alcohol and D (ratio (IU) of A to D ; 20 : 1).
