This International Standard specifies a method for the determination of the contents of free α-, β-, γ-, and δ-tocopherols and tocotrienols (referred to jointly as tocols) in animal and vegetable fats and oils (referred to hereinafter as fats) by high-performance liquid chromatography (HPLC). For products containing tocopherol or tocotrienol esters, it is necessary to carry out a preliminary saponification. NOTE A suitable method involving a cold saponification procedure is described in Annex B for information only.