Simultaneous Determination of Serum Retinol, Tocopherols, and Carotenoids by HPLC

Epidemiological studies have confirmed that dietary supplementation with vitamin E significantly inhibits oxidation of low-density lipoproteins (
1
) and reduces the risk of atherosclerosis (
2
) and coronary heart disease (
3
). Retinol and β-carotene (β-caro) are important micronutrient vitamins in reducing the risk of age-related macular degeneration (
4
) and cancer (
5
). The simultaneous determination of retinol, tocopherols, and carotenoids by high-pressure liquid chromatography (HPLC) using ultraviolet-visible absorbance (UV-VIS) detection has become the method of choice for investigators interested in determining fat-soluble vitamin levels in health and disease (
6
). This method achieves the desired separation and provides quantitation of numerous fat-soluble vitamins in biological specimens (
7
). Furthermore, the performance characteristics of the method have been extensively studied by the National Institute of Standards and Technology (NIST/NCI Micronutrients Measurement Quality Assurance Program, Chemistry B208, Gaithersburg, MD), which now supplies both quality-control material and offers proficiency testing for multiple analytes, as well as workshops on HPLC analysis of these analytes.