Quantification of Tocopherols in Oils

Tocopherols content was carried out with HPLC according to the method described by Dimić et al. [4 (link)]. The sample in n-hexane solution (1%, m/v) was injected into the chromatographic system. The analysis was performed using a 1200 series liquid chromatograph manufactured by Agilent Technologies (Palo Alto, CA, USA), equipped with a fluorescence detector. The separation was done on a LiChrospher Si 60 (250 mm × 4 mm, 5 μm) column (Merck, Darmstadt, Germany). The fluorescence detector was set at 290 nm excitation wavelength and 330 nm emission wavelength. Peaks were identified separately based on retention times determined for α-, β-, and γ-tocopherol standards (Merck, Darmstadt, Germany). The amounts of tocopherols in the extracts were calculated as mg tocopherols in a 100 g oil sample.