Validation of HPLC method for the determination of retinol in different dietary supplements

This paper proposes a simple HPLC method for the identification of vitamin A in dietary supplements, which does not imply thout saponification of the samples in order to preventing their degradation. The method was applied to the determination of the retinol concentration in five commercial products containing known amounts of vitamin A, under the following chromatographic conditions: werw used C18 column, a mobile phase consisted of methanol/water 95:5 (v/v) and UV (DAD) set at 325 nm. The linearity range was established between 0.05-10 mu g/mL for all-trans-retinoland prior to the analysis. The extraction was made performed with water: n-hexan 5:1 (v/v) prior to the analysis. The limit of quantification for trans-retinol was of 20 ng/mL and for retinyl acetate (internal standard) was of 50 ng/ml. Rapid determination of vitamin A by through the chromatographic method represents a good solution for its quantification in the different dietary supplements.