Abstract
In Order to eliminate α-tocopherol from vitamins A and D, application of ion exchange chromatography using strongly basic anion exchange resin Amberlyst A-26 with iso-propanol was examined. α-Tocopherol was adsorbed on the Amberlyst A-26 column, whereas unadsorbed vitamins A alcohol and D were eluted quantitatively by subsequent washing of the column with iso-propanol. Although a large part of α-tocopherol was removed by ion exchange chromatography, some α-tocopherol-degradation products, Which cause interference in the color reaction by SbCl_3 acetyl chloride reagent, were eluted with viamins A alcohol and D. However both the degradation products of α-tocopherol and A alcohol were separated from vitamin D by gel filtration on the Sephadex LH-20 column in chloroform. When α-tocopherol was removed from vitamin D by ion exchange chromatography on Amberlyst A-26 prior to the purification by the gel filtration and the Florex XXS adsorption chromatography (Vitamins 42,99 (1970)) was used, the recovery of vitamin D from mixtures contaning D_2 and α-tocopherol was almost satisfactory. This method will be applicable to the determination of vitamin D in the presence of vitamin A and α-tocopherol.
