Simultaneous evaluation of vitamins A and E in human plasma by normal phase HPLC

The production of toxic oxidants such as H2O2; OH. and O2.- which follows aerobic metabolism is highly enhanced in aging, alcohol consumption and in a variety of degenerative diseases including neoplasias. Among the different antioxidant agents that in human organisms counterbalance the oxidative stress, which damages lipid, protein and DNA, are included beta-carotene, alpha-tocopherol, glutathione, ascorbate, ubiquinol and specific enzymes such as superoxide dismutase, catalase and glutathione peroxidase. In particular, vitamins A and E are the most important lipid-soluble antioxidants in human tissues protecting polyunsaturated fatty acid from peroxidation. In this paper we report an improved method, obtained after modification of a normal phase HPLC method, which allows the simple and rapid simultaneous evaluation of vitamins A and E in plasma. The separation of vitamins is achieved by eluting the HPLC column with a linear gradient from 1 to 5% isopropanol in n-hexane. The eluate is simultaneously monitored by U.V. and fluorescence detection to identify and quantify vitamins A and E, respectively.