DETERMINATION OF TOCOPHEROLS IN VEGETABLE-OILS

A rapid (ten minute) and selective method for measuring individual tocopherols found in vegetable oils has been developed using High Performance Liquid Chromatography (HPLC) with ultraviolet absorbance detection. The samples are analyzed directly following dissolution in the mobile phase. α -and γ-tocopherols are quantitated based upon their peak areas relative to standard calibration curves. The measurement of β - and δ-tocopherols in the samples is also based upon the calibration data for the α - and δ-tocopherol standards since the individual β- and δ- standards were unavailable. The data obtained are compared with the total tocopherol content as found by a standard colorimetric procedure. The results indicate the HPLC method to be more reliable in the measurement of samples with high α -tocopherol levels. Soybean, safflower, sunflower, cottonseed, corn, peanut and olive oils have been examined using this method. © 1979 American Oil Chemists' Society.