The determination of vitamin E in food by colorimetry and gas-liquid chromatography

Abstract

Two methods for the determination of vitamin E in food are described: a colorimetric procedure for determining total tocopherols, based on their reaction with iron(III) chloride and bathophenanthroline (4,7-diphenyl-1,10-phenanthroline), and a gas-liquid chromatographic method for determining individual tocopherols. Techniques for the removal of interfering substances such as sterols and tocopherol dimers are given and results obtained by both methods for the vitamin E contents of some uncooked foods are compared. A complete determination can be carried out in 1 day by colorimetry and in 2 days by gas-liquid chromatography.