Isomeric Forms of Carotene and the Further Purification of Vitamin A

Abstract

CALCIUM hydroxide or calcium monoxide are splendid adsorbents for carotene. One chromatographic adsorption suffices to bring about a complete separation of - from -carotene. The -form has thus been isolated in an absolutely pure state, showing a melting point of 183° uncorr., 187° corr. The absorption spectra of -carotene in antimony trichloride solution has up to now been described as showing characteristic bands, one at 590 m, the other at 542 m. We find that under the same conditions, pure - and pure -carotene each give in reality only one of these bands. That one at 590 m belongs to the compound, the other at 542 m to the compound.