2, 5, 7, 8-Tetramethyl-2-(2′-carboxyethyl)-6-hydroxychroman (α-CEHC), the water-soluble metabolite of α-tocopherol (α-TOH) with a shortened side chain but an intact hydroxychroman structure, has been identified in human urine and are thought to be produced in significant amount at excess intake of α-TOH. In previous studies, CEHCs in biological specimens were measured by HPLC, GC− MS or LC− MS, preceded by a ...