Spectrofluorometric and high-performance liquid chromatographic determination of all-rac-α-tocopheryl acetate in virgin olive oil

A high-performance liquid chromatographic (HPLC) method was developed for the analysis of all-rac-α-tocopheryl acetate in olive oil. After extraction of all-rac-α-tocopheryl acetate from olive oil into hexane/ethyl acetate (4:1, v/v), it was measured with HPLC-diode array detection and regular external standard calibration and confirmed with liquid chromatography-mass spectrometry. Spectrofluorometric and standard addition methods were also used to quantify all-rac-α-tocopheryl acetate in olive oil. A standard addition method is based on fortification of known concentrations of all-rac-α-tocopheryl acetate in a sample. The concentrations (30.4±1.2 μg/mL) of all-rac-α-tocopheryl acetate determined with the HPLC method were comparable with those (32.6±1.1 μg/mL) with the spectrofluorometric method. Standards were checked for linearity giving correlation coefficients of higher than 0.999 in a concentration range from 0.5 to 20 μg/mL.