Analysis of beta-carotene in medical food by liquid chromatography with matrix solid-phase dispersion

A liquid chromatographic method is described for analysis of beta-carotene in medical food. The nutrient is extracted from medical food without saponi fication by matrix solid-phase dispersion and quantitated by isocratic norm al-phase chromatography with a Si 60 column and a mobile phase of hexane co ntaining 0.125% (v/v) isopropyl alcohol. The limit of quantitation is 0.02 mu g/mL at 436 nm, Standard response was linear over the concentration rang e of 0.02-1.0 mu g/mL (r(2) = 0.99998). Recoveries were determined on a zer o control reference material containing added p-carotene at various levels. Recoveries averaged 91.2% (n = 25) with coefficients of variation from 0.5 0 to 3.10%. The method provides a rapid, specific, sensitive, and easily co ntrolled assay for analysis of beta-carotene in fortified medical food. In addition, retinyl palmitate can be assayed simultaneously with an in-line f luorescence detector.