A New Spectrophotometric Method for the Determination of Vitamin A

Studies on the analysis of vitamins D. 2. The analytical purification of vitamin D by differential solubility, precipitation reactions, and chromatography

“…in diameter, would adsorb up to 320 i.u. of vitamin A, and Awapara, Mattson, Mehl & Deuel (1946) used the adsorption of vitamin A on floridin in a method for the analysis of margarine, no study appears to have been made of the very complex behaviour of vitamin A on this adsorbent. The purpose of the present study was to devise a simple chromatographic procedure for the quantitative separation of vitamins A and D on floridin.…”

Pharmaceuticals and Natural Drugs

“…Various procedures have since been developed utilizing the ultraviolet absorption spectrum of vitamin A for its estimation. The preparation of vitamin A-free blanks by chromatographic adsorption has recently received the attention of Awapara et al (8) as a means of improving ultraviolet absorption procedures. Wilkie (210) has reviewed the results of collaborative assays both on the ultraviolet absorption and the Carr-Price methods.…”

Chemistry of glycerol dichlorohydrin as a reagent for the determination of vitamin A

“…acyl halldes and other compounds, (2) to determine the struc tural requirements necessary In glycerol derivatives to pro duce good color when nixed with a vitamin A solution, (3) to determine the effect of various solvent-reagent ratios on the absorption spectra of the products of the reactions of vita min A with activated glycerol dlchlorohydrln, (4) to deter mine the effect of added impurities on the development of color, and (5) to determine the probable mechanism of the re action of vitamin A with activated glycerol dlchlorohydrln.…”