CONCURRENT LIQUID-CHROMATOGRAPHIC SEPARATION AND PHOTODIODE-ARRAY DETECTION OF RETINOL, TOCOPHEROLS, ALL-TRANS-ALPHA-CAROTENE, ALL-TRANS-BETA-CAROTENE AND THE MONO-CIS ISOMERS OF BETA-CAROTENE IN EXTRACTS OF HUMAN PLASMA

In this report we describe the development of a method for the concurr ent reversed-phase high-performance liquid chromatographic separation and photodiode array detection of human plasma retinol, tocopherols an d carotenes. For a single sample injection, retinol, retinyl acetate, alpha-tocopherol, gamma-tocopherol, alpha-tocopheryl acetate, all-tran s-alpha-carotene and all-trans-beta-carotene, as well as the mono-cis geometrical isomers of beta-carotene were separated and detected. Anal ytical separations were performed at a subambient temperature (0 degre es C) over a Suplex pKb-100 reversed-phase analytical column with an i socratic mobile phase of methanol-methyl tert.-butyl ether-water (80:2 0:5, v/v/v) at a flow-rate of 0.8 ml/min for 60 min. Standards and sam ples were reconstituted in ethanol, and typically, 50 mu l was injecte d for analysis. By HPLC, compounds of interest were clearly resolved a nd detectable at the picomole level. (C) 1997 Elsevier Science B.V.