ABSTRACT
Bunnell (1) in a 1971 review of procedures for analysis of vitamin E stated, “New or modified tocopherol assay procedures still appear at a frequent rate, even though vitamin E has been with us for over 40 years. The development of reliable assay methodology has been an evolutionary process which has achieved its greatest rate of development in the last 10 years.” Now, 70 years after the first characterization of vitamin E, methodology is still in an evolutionary stage and the number of method papers continues to grow rapidly. At the time of Binnell’s review, gas chromatographic (GC) methods for vitamin E analysis were rapidly gaining acknowledgment as the best approach for quantification of the tocopherols and tocotrienols. High-performance liquid chromatographic (HPLC) procedures were not yet in common use. Bunnell (1) reviewed only chromatographic methods, which included paper, thin-layer, column, and GC procedures. For final quantitation, after resolution by paper, thin-layer, or column techniques, Emmerie-Engel or bathophenthroline reagents were usually employed for chromophore development. For GC procedures, detection was by flame ionization.
