Methods for analysis of cancer chemopreventive agents in human serum

Sixty commercially available and five experimental liquid chromatography columns were evaluated for the separation and recovery of seven carotenoid compounds. Methanoland acetonitrile-based solvents (either straight or modified with ethyl acetate or tetrahydrofuran) were compared to determine which solvent systems and which columns provided better selectivity and recovery. Methanol-based solvents typically provided higher recoveries than did acetonitrile-based solvents. Polymeric C,g phases generally provided better selectivity for the diflScult separation of lutein and zeaxanthin than did monomeric Cjg phases.