Separation of RRR -α-Tocopherol by Chiral Chromatography

• Published in: Journal of AOAC International 2020-09, Vol.103 (5), p.1288-1292
• Main Authors: Gill, Brendon D, Indyk, Harvey E
• Format: Article
• Language: English
• ISSN: 1060-3271; 1944-7922
• DOI: 10.1093/jaoacint/qsaa055

BACKGROUNDα-Tocopherol can exist as eight possible stereoisomers due to the presence of three chiral carbons. Regulations and industry guidelines necessitate that dietary vitamin E intakes be based on the vitamin E activity of RRR-α-tocopherol. Food products fortified with synthetic all-rac-α-tocopherol or all-rac-α-tocopheryl acetate during manufacturing will require chiral separation of the α-tocopherol stereoisomers for accurate estimation of vitamin E activity. OBJECTIVEThe development of an HPLC method utilizing a chiral column for the chromatographic separation of RRR-α-tocopherol from other α-tocopherol stereoisomers. METHODNormal phase liquid chromatographic separation using a polysaccharide-based chiral column with fluorescence detection of α-tocopherol stereoisomers. RESULTSThe described chromatographic method achieves baseline resolution of RRR-α-tocopherol from its stereoisomers. Method selectivity, precision, and robustness were evaluated and acceptable performance was achieved. CONCLUSIONSThe chromatographic method was found to be suitable for application where both RRR-α-tocopherol content and total α-tocopherol content are required for routine compliance testing. HIGHLIGHTSA robust and precise chomatographic method for the baseline resolution of RRR-α-tocopherol from its stereoisomers was acheived.