[Determination of vitamin E in juices by high performance liquid chromatography (HPLC)]

A modified method for the determination of tocopherol(vitamin E) in juices by high performance liquid chromatography(HPLC) has been proposed in this paper. The juice samples were deproteinized with ethanol and extracted with hexane. Organic layer was evaporated to dryness with nitrogen after it was separated. Then the residue was redissolved with methanol and injected into a reversed-phase HPLC equipped with a C18 column. The tocopherols were eluted with methanol mobile phase at a flow rate of 1.0 ml.min-1 and detected by fluorescence(lambda exc = 295 nm, lambda em = 330 nm). A good linearity was shown between the concentration of tocopherol and the peak height at the concentration range of 0.2-2.2 micrograms.ml-1(r = 0.9995, n = 5). The recovery rate was more than 96.8%, and impurities in the samples were separated completely. This method is sensitive, simple and stable.