Reversed-phase high-performance liquid chromatographic identification of lutein and zeaxanthin stereoisomers in bovine retina using a C30 bonded phase

An efficient reversed-phase high-performance liquid chromatographic assay with ultraviolet detection at 450nm for simultaneous determination of lutein and zeaxanthin stereoisomers in bovine retina is described. The procedure involves rapid and careful one-step hexane extraction of the carotenoids from the homogenized liquid and enrichment by on-line solid phase extraction on a polystyrene cartridge. The substances were eluted at a flow rate of I ml/min with acetone-water (85.15, v/v) on a C-30 reversed-phase column. C-30 phases exhibit superior shape selectivity for the separation of carotenoid stereoisomers compared with conventional C-30 phases. For comparison a mixture of iodine-isomerized lutein and zeaxanthin standards was separated. (C) 1998 Elsevier Science B.V. All rights reserved.