Tocopherol and Tocotrienol Contents
Tocopherols were determined by HPLC with reported
procedure [22].The HPLC system of Merck Hitachi(Darmstadt, Germany) consisted of pump L-6000: F-1000
fluorescence spectrophotometer set to excitation wavelength
295 nm and emission wavelength 330 nm; D-2000
integrator: Lichrospher 100 Diol pre-column with particle
size 5 lm, length 4 mm, and internal diameter 4 mm;
Lichrospher 100 Diol pre-column with particle size 5 lm,
length 250 mm and internal diameter 4 mm; Rheodyne
7125 injector and a 20 ll sample loop. The system was
operated at 21 ± 1 C, with mobile phase n-hexane/tertbutyl
methyl ether 94.4:5.6 V/V at a flow rate of 1.2 ml/
min. The sample size ranged from 5 to 20 ll of extracted
oil. A calibration curve was prepared by injecting known
concentrations of standard tocopherols. The concentration
of tocopherols and tocotrienols in the samples were calculated
from equations derived from individual tocopherol
standards.