Analysis Of Vitamin E Metabolites By Liquid Chromatography-Tandem Mass Spectrometry

Naturally occurring forms of Vitamin E are metabolized to various carboxychromanols and conjugated carboxychromanols. Recent studies showed that vitamin E metabolites, especially the long-chain carboxychromanols are more bioactive than unmetabolized vitamin E forms. It is necessary to quantify vitamin E metabolites in biological environment. Here a simple and effective extraction method was developed to achieve extraction efficacy of more than 90% of various forms of vitamin E and metabolites with less than 10% inter- or intra-day variation. An LC-MS/MS assay was developed and optimized to acquire best sensitivity for the detection of vitamin E and metabolites. This method allows simultaneous detection of all carboxychromanols and sulfated carboxychromanols. Using the optimized extraction and LC-MS/MS analysis conditions, vitamin E metabolites in plasma or feces of animals fed with γT, γTE, δT or δTE-13\u27 were analyzed. Results showed that, the major metabolites in the blood were conjugated g-CEHC and sulfated long chain carboxychromanols