Measurement of the vitamin E metabolites, carboxyethyl hydroxychromans (CEHCs), in biological samples

Metabolites of α- and γ-tocopherol, 2,5,7,8-tetramethyl-2-(2'-carboxyethyl)-6-hydroxychroman (α-CEHC) and 2,7,8-trimethyl-2-(β-carboxyethyl)-6-hydroxychroman (γ-CEHC), respectively, are produced in the liver and have been measured in biological fluids and tissue. Compared to α-tocopherol concentrations, metabolite concentrations are as much as a factor of a thousand lower, requiring extremely sensitive methodology to attain accurate measurements. This unit presents a protocol for CEHC extraction from biological samples, and describes very specific and sensitive HPLC/MS analysis.