DETERMINATION OF CAROTENOIDS IN VEGETABLE FOODS AND PLASMA

In this paper a HPLC method for the determination of lutein, zeaxanthi n, beta-cryptoxanthin, alpha-carotene, beta-carotene and lycopene in m ixed vegetables and fruit and in human plasma is described. The carote noids were well separated and the separation was achieved within fifte en minutes using a HPLC system consisting of a 5 mu m Vydac 201TP54 C- 18 column, an UV detector; methanol-tetrahydrofuran (95:5 v/v) as mobi le phase and a flow rate of 1.0 ml/min. The validity of the separation method was determined by evaluating the linearity of the calibration graphs of each carotenoid (between 0.1 and 1.0 mu g/ml for all compoun ds except lycopene between 0.1 and 0.8 mu g/ml, r=0.999) and the accur acy of the chromatographic response (CV <10%). The reproducibility of the retention times was also good. In the foods samples the extraction procedure was very effective whereas, the saponification step signifi cantly damaged some of the carotenoids. In the plasma the extraction a nd separation of these compounds were also effective and the qualitati ve data obtained comparable with those reported in literature. The use of echinenone as internal standard helped to improve quality control.