Identification and estimation of tocopherols by gas‐liquid chromatography

Abstract

Abstract A gas chromatographic method is described for the identification and estimation of the individual tocopherols as their trimethylsilyl (TMS) ethers. The TMS ethers are prepared by dissolving the sample in a mixture of hexamethyl‐disilazane, trimethylchlorosilane, and anhydrous pyridine (2:1:10), and allowing it to stand for at least 15 min. The separations described were made at 235C on 0.08 in. I.D. ȕ15 ft silanized glass columns packed with either 0.5% Apiezon L or 2% SE‐30 on 110/120 mesh Anakrom (acid and base washed, and silanized). Retention data, obtained either by chromatographing known compounds or by prediction using the Kovȥts Retention Indices, are presented for tocol, tocotrienol, and all 14 possible methylated tocols and tocotrienols. The quantitative results from the analyses of two standard mixtures are also presented. The application to naturally occurring tocopherols is illustrated by chromatograms of partially purified fractions from soy oil, wheat germ oil, whole wheat flour, and corn meal.