An improved colorimetric procedure for the analysis of vitamin A

Abstract

Factors affecting the reaction between antimony trichloride and 2,3-dichloropropanol (2,3-DP) with retinol and related compounds were examined. It is shown that purified 2,3-DP with the addition of antimony trichloride produces a stable colour complex with retinol absorbing at 555 nm. A tentative scheme for the reaction mechanism and the possible structure of the complex are also presented.