DETERMINATION OF CAROTENOID-PIGMENTS, RETINOL, AND ALPHA-TOCOPHEROL IN FEEDS, TISSUES, AND BLOOD-SERUM BY NORMAL-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A normal phase HPLC method employing a hexane:ethyl acetate mobile pha se solvent gradient for the simultaneous separation and quantification of carotenoid pigments and vitamins A and E has been developed. The g radient consists of a 10-min linear change from 1 to 2 mL/min and 95:5 to 70:30 hexane:ethyl acetate mobile phase, which is followed by 7 mi n of isocratic mobile phase of 70:30 hexane:ethyl acetate at 2 mL/min. The stationary phase consisted of a 4-mu silica column. A photodiode array detector generated simultaneous chromatogram data at three wavel engths (294, 325, and 445 nm) with broad spectrum data at peaks. The m ethod produced good separation of trans-lutein and zeaxanthin.