Simultaneous measurement of retinol, alpha-tocopherol, carotenoids and xanthins in human plasma by using an isocratic reversed-phase HPLC method

We describe a simple, specific, and sensitive isocratic reversed-phase HPLC method for simultaneous determination of retinol, alpha-tocopherol, carotenoids and xanthins in human plasma. Chromatographic separation was achieved by combining two Phenomenex Synergy 4 u Hydro-RP 80A columns in series. Mobile phase consisted of acetonitrile-methanol-chloroform (60:25:15, v/v/v) containing 0.01% (w/v) BHT at a flow rate of I ml/min. Absolute and relative recoveries were 80-103%. Intra-assay CVs were 1.5-6.1% and inter-assay CVs 3.1-11.3%, respectively. The method can be used in large population studies.