Separation of beta- and gamma-tocopherols in serum by high performance liquid chromatography

A simple and sensitive high performance liquid chromatographic method for the analysis of tocopherols (alpha, beta, gamma and delta) in serum with UV detection is described. In normal phase mode excellent separation of positional isomers (beta and gamma) was achieved by adjusting the proportion of isopropanol in the mobile phase. Detection limits for both beta and gamma were 0.62 mg/L and 0.42 and 1.2 mg/L for alpha and delta isomers, respectively. Measurement of all the tocopherol structural isomers (alpha, beta, gamma and delta) in a sample required only 400 microL of serum and each run was completed in less than 22 min.