Analysis of tocopherols in vegetable oils by high‐performance liquid chromatography: Comparison of fluorescence and evaporative light‐scattering detection

Abstract

A comparison of the responses of an evaporative lightscattering detector (ELSD) and a fluorescence detector for tocopherols in vegetable oils by high-performance liquid chromatography is presented. The tocopherols were separated from acylglycerols by gel-permeation chromatography (GPC). The tocopherol fraction was collected off a set of four GPC columns 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 obtain quantitative data. The fluorescence detector was ten times more sensitive than the ELSD. y-Tocopherol was the major tocopherol detected 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 favorably with the literature values.

Analysis of tocopherols by gas-liquid and high-performance liquid chromatography: a comparative study

“…In this study, mean levels of 329 ppm and 349 ppm were detected by HPLC and GLC, respectively. Literature data on the level of this homologue vary widely between 222 and 436 ppm [11,15].HPLC and GLC data for peanut and corn oil corresponded quite well and are in good agreement with those reported by Machlin [12] but lower than the values of Clough [11]. The same conclusion can be drawn for the majority of the corn oil samples.…”

Analytical strategies to assess the functional metabolome of vitamin E

“…A comparative study showed ELSD sensitivity to be by far inferior to FL detection [120]. Accordingly, the observed sensitivity of various detectors resulted in the following order of magnitude: ECD > FL > UV > ELSD.…”

The Modern Art of Identification of Natural Substances in Whole Plants

“…Low-polar compounds can be analyzed either by NPLC or RPLC. NPLC is particularly interesting for the separation of geometrical isomers and several reports have described for a long time the use of silica as adsorbent for the analysis of tocopherol and tocotrienol isomers (Weber 1984;Balz et al 1993;Tangney et al 1979;Chase et al 1994). Their retention is ensured by the use of a mobile phase containing a high proportion of apolar solvent (e.g., 98.8 % hexane) and a small proportion of polar modifier (e.g., 1.2 % isopropanol) (Weber 1984).…”