ISOLATION OF TOCOPHEROLS FROM WHEAT-GERM OIL BY RECYCLE SEMIPREPARATIVE SUPERCRITICAL FLUID CHROMATOGRAPHY

Isolation of tocopherols wheat-germ oil was achieved by recycle semi-preparative supercritical fluid chromatography using two 250 mm × 10 mm I.D. columns packed with 5-μm silica gel. β-Tocopherol was fractionated after recycling twice and α-tocopherol after two additional recycles. Peak assignment was performed by comparing the UV spectra of the fractionated substances, which were obtained during the chromatographic run using a photodiode-array UV detector, with those of standard tocopherols. The identification of the fractionated substances was confirmed from the IR spectra. The purities of α- and β-tocopherols were found to be about 85 and 70%, respectively, by capillary gas chromatography. © 1990.