Purity and Stability of Commercial Carotene

CAROTENE , an important commercial product, is sold in considerable quantities for medicinal purposes, for adding vitamin A potency to animal Feeds, as a standard for vitamin A, for preparing reagents and standardizing photoelectric or visual colorimeters in the determination of carotene, and for other purposes. It is readily obtainable in crystalline or amorphous forms or dissolved in an oil. The composition, stability, and purification needed are of importance both from a scientific and a practical standpoint. The stability of carotene dissolved in oils, and in other solvents has been studied (1, 4), but little work has been, done on solid carotene. Composition Commercial carotene can be purchased In sealed glass tubes which have been evacuated. Analyses of one sample of such carotene were reported by Miller, ZscheiLe, and Hogness (6), who stated that it contains 6 per cent colorless impurities, 81 per cent s-carotene, and 13 per cent a-carotene. Several samples of commercial carotene were ...