Separation of individual tocopherols from human plasma and red blood cells by thin-layer and gas-liquid chromatography.

A thin-layer chromatography-gas-liquid chromatography system has made it possible to separate the individual tocopherols for qualitative and quantitative determination in blood plasma and red blood cells. The peak of the individual tocopherols found in plasma and red blood cells were identified by their RF values and comparing their relative retention times with that of 5,7-dimethyltocol which served as an internal reference standard. The detection limits for the tocopherol with the hydrogen flame detector was found to be in the range of 0.03 ,ug. Fat-soluble reducing substances which constitute the major source of interference in the commonly used methods do not interfere with the separation of the tocopherols.