Tandem mass spectrometry is applied to the tocopherols and representative tocotrienols of the vitamin E family. The collision-induced dissociation/mass analysed ion kinetic energy spectra generated from three ions in the electron impact ionization spectra of 5,7,8-trimethyltocol, 5,7,8-trimethyltocotrienol, 5,7-, 5,8- and 7,8-dimethyltocol and 7,8-dimethyltocotrienol are described. The technique allowed direct physical characterization of each class of tocochromanol, and in the case of monomethyltocols differentiation of 5-methyltocol from the 7- and 8-methyltocol isomers, and its value in analysis of biological tissue extracts is established.

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