ABOUT TRAINING IN THE DETERMINATION OF TOCOPHEROLS IN VEGETABLE RAW MATERIAL BY HPLC

Tocopherols, which are important biologically active substances, play the role of antioxidants. Synthesized tocopherols are usually in esterified form; their sample preparation for quantification by high performance liquid chromatography includes high temperature alkaline hydrolysis. Sample preparation of oil-containing objects having natural tocopherols in an unesterified form is carried out by direct extraction in a non-polar solvent. In this work, we determined the content of tocopherols in natural materials (the method of analysis of viscous particles) using the alkaline hydrolysis method and the direct extraction method in a non-polar solvent. It was shown that the use of normal-phase HPLC with a prepared extraction sample in hexane and low-temperature exposure allows us to determine both the total content of tocopherols and its individual forms. This option is less time consuming, requires fewer reagents, which significantly affects the cost of the analysis. It is possible to determine only the total number of tocopherols. At the same time, overestimated results were obtained, which are probably associated with the destructive destruction of both tocopherols and tocotrienols present in plants of plant origin, and one large peak, including all products, is observed in the chromatograms.