The analysis of tocopherols in corn oil and bacon fat by thin‐layer chromatography and spot density measurement

Publisher Website
Google Scholar
Abstract
Summary: The two major tocopherols (α and γ forms) present in corn oil were separated, after removal of interfering lipids, by thin‐layer chromatography (TLC), and detected on the TLC plate by spraying with Gibbs' reagent (2,6‐dichloro‐p‐benzoquinone‐4‐chlorimine). Quantitation was achieved by densitometric scanning of the coloured spots, using a calibration curve prepared from reference samples of the pure α‐ and γ‐tocopherols. α‐tocopherol, added to bacon fat, was quantitatively recovered without measurable loss during the analysis. Other antioxidants commonly added to foodstuffs, with the exception of BHA and BHT, were not extracted. The method described has a detection limit of 20 ppm of α‐ or γ‐tocopherol for a given fat sample, hence permits the quantitation of either tocopherol in vitamin E‐rich materials, such as vegetable oils, but lacks the sensitivity to detect the trace amounts of tocopherols normally present in animal fatty tissues.