ANALYSIS OL TOCOPHEROLS IN VEGETABLE-OILS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY - COMPARISON OF FLUORESCENCE AND EVAPORATIVE LIGHT-SCATTERING DETECTION

A comparison of the responses of an evaporative lightscattering detect or (ELSD) and a fluorescence detector for tocopherols in vegetable oil s by high performance liquid chromatography is presented. The tocopher ols were separated from acylglycerols by gel-permeation chromatography (GPC). The tocopherol fraction was collected off a set of four GPC co lumns with a mobile phase of methylene chloride before separation on a normal-phase silica column with a mobile phase of hexane/isopropanol, 99.7:0.3 (vol/vol). An internal standard of 5,7 dimethyltocol, which was detected by both the ELSD and fluorescence detector, was used to o btain quantitative data. The fluorescence detector was ten times more sensitive than the ELSD. gamma-Tocopherol was the major tocopherol det ected in the vegetable oils studied and ranged from 24.1-93.3 mg/100 g . The amounts of tocopherols found in the vegetable oils agreed favora bly with the literature values.