The same HPLC system as that used for the analysis
of oryzanols and a Shim-pack (LC-NH2 (M)) column
(4.6 mm i.d. 25 cm) was used in the normal-phase with
the solvent system, n-hexane/isopropanol (96:4; v/v) and
at a flow rate of 1 ml/min. The UV detector was set at
297 nm (Renuka Devi, Suja, Jayalekshmy, & Arumughan,
2000). Peak identification was based on comparison of RT
values with authentic standards of tocopherols and tocotrienols.
The various vitamin E forms were quantitated
based upon the peak areas relative to standard calibration
plots by an external standard method. Samples were redissolved
in n-hexane and 20 ll of the solutions were injected
into the HPLC column