LIQUID-CHROMATOGRAPHIC DETERMINATION OF CAROTENOIDS IN HUMAN SERUM USING AN ENGINEERED C-30 AND A C-18 STATIONARY-PHASE

A C-30 stationary phase was specifically engineered for carotenoid sep arations, and carotenoid measurements using this column are compared w ith those obtained using a somewhat more conventional C-18 column. Bot h methods were used to contribute measurements for the certification o f carotenoids in Standard Reference Material 968b, Fat-Soluble Vitamin s and Cholesterol in Human Serum. Analytes were extracted from the ser um into hexane. Measurements on the C-18 column were made using a grad ient of acetonitrile, methanol, and ethyl acetate, which is described in detail elsewhere. Measurements on the C-30 column were made using a gradient of water, methanol, and methyl tert.-butyl ether.