ABSTRACT
A microprocedure for the simultaneous determination of retinol and alpha-tocopherol in 100 ?l human plasma by reversed phase high pressure liquid chromatography without precolumn is detailed in this paper. A solvent system of methanol/water (96:4) provides clear separation of these two fat soluble vitamins. The chromatogram is complete in 12 min. The retinol and al-pha-tocopherol are quantitated by the peak height ratio and weight ratio method using retinyl acetate as an internal standard. The coefficient of variation of ten determinations is less than 5%. The mean recovery of four different concentrations of retinol and alpha-tocopherol are 102.2110.3% and 95.8?9.9% respectively. This microprocedure should be useful for assessment of the nutritional status of these two vitamins and might help to elucidate the relationship between them.