A critical study of the Carr-Price reaction for the determination of β-carotene and vitamin A in biological materials

Abstract

Abstract The applicability of the Carr-Price reaction to the analysis of biological materials has been critically re-examined using the Evelyn photoelectric colorimeter. Excellent recoveries of crystalline β-carotene and vitamin A were obtained with reproducible results. The macroprocedure described was found satisfactory for routine analysis of blood plasma or serum. Preliminary saponification of plasma or serum was found to have no significant effect on the vitamin A or carotene concentrations in normal human plasma. Recent criticisms directed against the Carr-Price reaction as the basis for the quantitative determination of vitamin A and β-carotene in biological materials should take into account the carefully specified conditions which are essential to the successful application of this reaction. The studies referred to herein were conducted under the auspices of the International Health Division of the Rockefeller Foundation of New York City by the nutrition units of the Departments of Biochemistry and Medicine, Vanderbilt University School of Medicine, Nashville, Tenn.