Fast gradient normal-phase high pressure liquid chromatography for rapid baseline separation of vitamin E forms in palm-derived tocotrienol rich fractions (TRFs)

摘要

A rapid, accurate and precise normal phase high pressure liquid chromatographic method was developed and validated for the simultaneous determination of nine vitamin E forms comprised of alpha-tocomonoenol, alpha-, beta-, gamma-, and delta-tocopherols and alpha-, beta-, gamma-, and delta-tocotrienols in tocotrienol rich fractions (TRFs) derived from palm oil. The chromatographic separation of vitamin E was performed on a silica HPLC column thermostated at 40 degrees C using n-heptane and ethyl acetate as the mobile phase in a gradient elution mode. The calibration standard curves were linear over the concentration range from 0.1 to 1.0 mg mL(-1) for all vitamin E forms with overall R-2 > 0.9980. The percent relative standard deviation of the method repeatability was less than 2.0% and the recovery ranged between 90 and 110%. The instrument limit of detection and quantitation ranged from 0.04 to 0.05 mg mL(-1) and from 0.11 to 0.18 mg mL(-1) respectively. The separation was completed in 15 minutes with an additional 2 minutes for reequilibration. In conclusion, a method has been successfully developed and validated for the simultaneous analysis of nine vitamin E forms in palm oil which is suitable for routine quality control of all vitamin E forms in palm TRFs at different compositions.