Influence of extraction techniques on determination of alpha-tocopherol in animal feedstuffs

Methods were compared for alpha-tocopherol determination involving saponification in the preparation of feed extracts for high performance liquid chromatography. The effects of antioxidant and saponification times used were also examined. The data obtained showed that saponification before solvent extraction more efficiently released natural alpha-tocopherol from the feedstuffs than extraction before saponification. Increases in alpha-tocopherol content of 0--144% were obtained for the range of feedstuffs examined. Ascorbic acid and pyrogallol used as antioxidants gave similar results, and extraction efficiency was independent of the time of saponification within the range 5--40 min.