Determination of tocopherols, tocopherolquinones and tocopherolhydroquinones by gas chromatography–mass spectrometry and preseparation with lipophilic gel chromatography

Lipophilic gel chromatography using Sephadex LH-20 helps in separating α-, β-+γ-, and δ-tocopherol and also in separation of their oxidation products e.g. the tocopherolquinones or other oxidation products. This preseparation can help to overcome analytical problems due to the complexity of synthesis mixtures of tocopherol oxidation procedures as well as in separation of complex physiological matrices. Determination of the preseparated tocopherols, tocopherolquinones and tocopherolhydroquinones can then be achieved by means of GC–MS measurement of the free substances or their trimethylsilyl derivatives.