Simple high-performance liquid chromatographic method for the determination of tocotrienols in human plasma

摘要

A simple high-performance liquid chromatographic method using fluorescence detection was developed for the determination of vitamin E especially #epsilon#-,#gamma#- and #alpha#-tocotrienols in human plasma. The method entailed direct injection of plasma sample after deproteinization using a 3:2 mixture of acetonitrile-tetrahydrofuran. The mobile phase comprised 0.5% (v/v) of distilled water in methanol. Analyses were urn at a flow-rate of 1.5 ml/min with the detector operating at an excitation wavelength of 296 nm and emission wavelength of 330 nm. This method is specific and sensitive,with a quantification limit of approximately 40,34 and 16 ng/ml for #alpha#-,#gamma#- and #epsilon#-tocotrienol,respectively. The mean absolute recovery values were about 98% while the within-day and between-day relative standard deviation and percent error values of the assay method were all less than 12.0% for #alpha#-,#gamma#- and #epsilon#-tocotrienol. The calibration curve was linear over a concentration range of 40-2500,30-4000 and 16-1000 ng/ml for #alpha#-,#gamma#- and #epsilon#-tocotrienol,respectively.Application of the method in a bioavailability study for determination of the above compounds was also demonstrated.