Gas-liquid chromatographic determination of vitamin D in multivitamin preparations containing excess amounts of vitamin E.

Gas-liquid chromatographic (GLC) determination of vitamin D in multivitamin preparations containing excess amounts of vitamin E (a more than 2,500 weight ratio of dl-alpha-tocopheryl acetate to vitamin D) was investigated and a simplified routine method was established because the method reported previously (1) could not be applied to such special preparations. After applying the unsaponifiable matters of a sample to a phosphate-treated alumina column chromatography prepared according to MULDER et. al. (2), the eluate was evaporated and the residue was subjected to thin-layer chromatography (TLC) and GLC. When this method was applied to model preparations made by mixing vitamin D2 and dl-alpha-tocopheryl acetate (excess amounts), good results were obtained. Since the results on a commercial multivitamin preparation containing excess amounts of vitamin E were also satisfactory, it was confirmed that the proposed method could be used for simplified routine determinations.