DETERMINATION OF ALPHA-TOCOPHEROL IN PLASMA AND ERYTHROCYTES BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A reversed-phase high-performance liquid chromatographic method for the determination of alpha-tocopherol in plasma or erythrocytes with photodiode-array detection is described. Using this detector, information about the spectrum, absorption maxima and purity of the peak is obtained. Tocopherol was separated on a 5-mu m Spherisorb ODS-2 column with methanol as element at a flow-rate of 1.0 ml/min. As little as 100 mu l of plasma or 150 mu l of erythrocytes can be used for accurate analysis with direct extraction without saponification. The speed, specificity, sensitivity and reproducibility of this technique make it particularly suitable for the routine determination of alpha-tocopherol in plasma or erythrocytes.