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

A reversed-phase high-performance liquid chromatographic method for th e determination of alpha-tocopherol in plasma or erythrocytes with pho todiode-array detection is described. Using this detector, information about the spectrum, absorption maxima and purity of the peak is obtai ned. 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 anal ysis with direct extraction without saponification. The speed, specifi city, sensitivity and reproducibility of this technique make it partic ularly suitable for the routine determination of alpha-tocopherol in p lasma or erythrocytes.