SIMULTANEOUS MEASUREMENT OF 7 CAROTENOIDS, RETINOL AND ALPHA-TOCOPHEROL IN SERUM BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A reversed-phase high-performance liquid chromatography (HPLC) procedu re for the quantitative measurement in serum of seven carotenoids (lut ein, zeaxanthin, canthaxanthin, beta-cryptoxanthin, lycopenes, alpha-c arotene and beta-carotene), retinol, alpha-tocopherol and two internal standards (tocol and echinenone) has been developed. The geometric is omers, lutein and zeaxanthin, were completely separated as well as at least nine unidentified carotenoids. All compounds were resolved on an Adsorbosphere HS C-18 (3 mu m) column (250 x 4.6 mm I.D.) with a step gradient, 7.1 min after injection, from acetonitrile-methanol (60:40, v/v) containing 0.05% acetic acid to acetonitrile-methanol-dichlorome thane (45.6:30.4:24, v/v) containing 0.04% acetic acid, in a total run time of 23 min. Chromatograms at four different wavelengths (292, 325 , 450 and 473 nm) and spectra were monitored with a diode array detect or. Because of its specificity and sensitivity for a large number of c arotenoids, this procedure may be of interest for nutritional and epid emiological studies. Its speed and robustness make it suitable for ana lyses on large numbers of subjects.