フロリジルカラムクロマトグラフィーによる乳脂肪中のトコフェロールの定量におよぼすFeCl₃還元物質の影響

抄録

It was tried to simplify the determination of tocopherols in milk fat on ferric chloride and batho-phenanthroline reaction, because most tocopherol (95%) was α-type. FeCl₃-reducing substances other than tocopherols were determined with the same procedure as tocopherol described by us previously. Unsaponifiable matter corresponding to the total FeCl₃-reducing substances was fractionated by eluting with petroleum ether, benzene, and ethanol, in that order, through Florisil column. FeCl₃-reducing substances calculated as α-tocopherol were distributed approx. 21% in the petroleum ether, 60% in the benzene containing all of tocopherols, and 19% in the ethanol fraction. The benzene fraction was further separated on silicagel G thinlayer chromatography and α-and ϒ-tocopherol were determined. Total tocopherol content was approx. 45.0% (40_??_60%) of total FeCl₃-reducing substances and approx. 76.5% (64_??_88%) of that of the benzene fraction. It was conclusively found that there was a difficulty to simplify the determination procedure of tocopherol in milk fat and, unless FeCl₃-reducing substances other than tocopherols was removed, the determined values give erroneous high values. It is desirable to determine tocopherols separated from other FeCl₃-reducing substances by means of thin-layer chromatography in order to obtain the more correct values, although it is somewhat troublesome in the technique.