Analysis of primary metabolites of α-tocopherol in human urine by liquid chromatography-mass spectrometry

To investigate primary metabolites of α-tocopherol in human urine, the urine samples of five healthy volunteers after oral administration of 250 mg vitamin E once a day for seven days were collected within 0-6 h in the seventh day. The samples were purified through C₁₈ solid-phase extraction cartridge and analyzed by liquid chromatography-tandem mass spectrometry. α-Tocopheronic acid, 2,5,7,8-tetramethyl-2-(2′-carboxyethyl)-6-suphate-chroman (α-CEHC-sulphate), γ-tocopheronolactone, and 2,5,7,8-tetramethyl-2-(4′,8′,12′-trimethyl-12′-carboxy dodecanyl)-6-suphate-chroman were found in urine of volunteers as four primary metabolites of α-tocopherol. The method has shown to be promising for α-tocopherol detection with many desirable properties including high sensitivity and selectivity, thus providing a reliable pathway for further study in metabolism of α-tocopherol.