CHAPTER 15: Analysis of Vitamin E Metabolites

Enzymatic and non-enzymatic (free-radical-derived) metabolites of vitamin E are objects of increasing interest as both are indicators of the metabolism and biological functions of this fat-soluble vitamin. These include bioactive long-chain metabolites of alpha-tocopherol formed by the activity of cytochrome P450, which have recently been measured for the first time in human plasma using a new unbiased LC-MS/MS procedure. This chapter summarises the available knowledge on analysis strategies and techniques currently in use to measure the different types of metabolites of this vitamin so far identified and studied in biological samples.