30 - 



Mixtures of magnesia and Celite were effective for the separation 

 of carotenes in plant extracts and for the separation of certain xantho- 

 phylls from the extracts, (See Figures 1,2 and I, Jo) Columns of mag- 

 nesia plus Celite were employed to confirm and to extend the separations 

 effected in the sugar columns ' . They also served to remove traces 

 of chlorophyll that contaminated the carotenoid pigments separated in 

 the sugar columns. 



Properties of Pigaents Separated in the Sugar Columns 



For the isolation of the pigments separated in the sugar columns, 

 the individual colored zones were removed separately with a long spatula 

 and packed into short filter tubes. The pigments were then eluted with 

 methanolo With the green pigments, the residual petroleum ether in the 

 eluates was removed quickly with vacuum, and the wave lengths of the 

 absorption maxima were observed. The chlorophylls from various sources 

 were then compared by sorption of the mixtures in fresh columns of 

 powdered sugar. 



The eluates containing the carotenoid pigments were diluted with 

 a little petroleum ether, and the pigments were transferred to this 

 solvent by the addition of dilute salt solution. Unless they were 

 altered by magnesia, the pigments were then adsorbed in columns formed 

 by pressing a lg2 mixture of activated magnesia (Micron Brand Magnesium 

 Oxide) and nonsorptive siliceous earth (Celite 5U5) into glass tubes 

 about 3 cin„ in diameter and 20 cm„ tall. The carotenes were separated 

 by washing the pigments with petroleum ether; the xanthophylls were 

 separated by washing with petroleum ether plus 25 per cent acetoneo 

 (See Figures 1,2 and 1,3.) 



