抄録
For the purpose of investigation of the influence of contaminant in twenty-three longstored samples, including five synthetic oleovitamin A, five vitamin preparations and thirteen fish-liver oils, on vitamin A value, alumina-column chromatographic treatment was applied to the unsaponifiable matter of these samples and the vitamin A values estimated before and after the treatment were compared. It was found that the vitamin A values of two vitamin preparations and seven fish-liver oils were increased 0.4 to 5.1% by the treatment and that the vitamin A values of the other samples were little affected by the treatment. By these observations, it might be concluded that the application of alumina-column chromatographic treatment was not always necessary for these samples.
