Comparison Study on Methods for Pretreatment of Sample in HPLC Determination of Vitamin E in Vegetable Oil

Three pretreatment methods, i.e. saponification, solvent dilution method and solid phase extraction, used for HPLC determination of vitamin E in vegetable oil were studied comparatively. The method of solid phase extraction was found to be more rapid, simple, and with high accuracy, precision and good reproducibility. At the same time, the method was beneficial to the normal use of the column and the maintenance of the instrument. Solid phase extraction was proved to be the best among the 3 pretreatment methods for use in HPLC determination of vitamin E in vegetable oil.