Mar. i5,1925 Physical and Chemical Properties of Xanthophyll 
577 
To separate the xanthophyll from 
the petroleum-ether acetone solution 
1 liter of 80 per cent methyl alcohol 
is added, the solution is shaken three 
times, and the yellowish-green methyl 
.alcohol layer is drawn off each time. 
If the last extract is still quite yellow 
more extractions will be necessary. 
The methyl alcohol extracts are com¬ 
bined and placed in a 7-liter separa¬ 
tory funnel or a 5-gallon water bottle. 
The petroleum ether solution by fur¬ 
ther treatment may be used for the 
preparation of chlorophyll and caro¬ 
tin. 
The xanthophyll is extracted from 
the methyl alcohol by mixing the 
■combined xanthophyll extracts with 
4 to 6 liters of ether. This solution is 
shaken thoroughly, and a saturated 
aqueous sodium chloride solution equal 
in amount to the methyl alcohol is 
added. The ether layer containing 
the xanthophyll and traces of chloro¬ 
phyll will separate above and the 
aqueous methyl alcohol layer below\ 
The aqueous methyl alcohol layer is 
then run off. About 2 liters of ether 
are added to this aqueous methyl alcohol 
solution and shaken again; more of 
the salt solution is added and allowed 
to stand a half hour, when the ether 
layer will have separated. The ether 
extraction is repeated if necessary. 
If a 5-gallon bottle is used the aqueous 
methyl alcohol layer can be siphoned 
off into another bottle and then the 
ether solution of xanthophyll may be 
poured into a separatory funnel, where 
the last traces of methyl alcohol and 
acetone may be washed from the 
ether. 
The ether solutions of xanthophyll 
are all combined in a 4 or' 6 liter 
separatory funnel and washed several 
times with water to remove alcohol 
and traces of acetone. The yellowish- 
green ether solution which contains 
the xanthophyll and some chloro¬ 
phyll b is now dried by shaking with 
anhydrous sodium sulphate (100 to 
200 gm.). After pouring the ether 
solution from the sodium sulphate it 
is shaken with 50 c. c. of concentrated 
methyl alcoholic potash. 
Saponification is best carried out at 
room temperature in a gallon bottle or 
in a separatory funnel and is done in 
order to remove chlorophyll b, the 
potash salt of which is soluble in water. 
The water soluble salt of chlorophyll 
b is now washed from the ether, 100 to 
200 c. c. of water being used for each 
of several washings. The xanthophyll 
remains in the ether. 
The ether solution is dried with 
anhydrous sodium sulphate, then fil¬ 
tered and evaporated (using diminished 
pressure toward the last) to about 25 
c. c. on a water bath at a temperature 
not exceeding 50° C. The xanthophyll 
should not remain in contact with 
ether long, for experiments reported 
below show that ether will oxidize the 
xanthophyll and cause a lower yield. 
The concentrated ether solution of 
xanthophyll is mixed with 200 to 300 
c. c. of absolute methyl alcohol while 
the solution is still in the water bath 
and the ether is removed under re¬ 
duced pressure. The methyl alcohol 
solution is filtered through a Buchner 
funnel with suction while hot to remove 
impurities and the last traces of ether. 
The concentrated solution of xantho¬ 
phyll in methyl alcohol is now allowed 
to stand in the ice chest for a day or 
more, when beautiful crystals of 
xanthophyll will have separated. In 
order to make the separation complete 
a little water is added, when the xantho¬ 
phyll will form crystalline aggregates 
which are arranged radially. On stand¬ 
ing for a day or two, the aggregates 
gradually change to the usual form of 
leaf clusters. The yield of xanthophyll 
when separated from the above mother 
liquor by filtering and washing with 
petroleum ether to remove traces of 
fats, etc., is 0.5 to 0.8 gm., or more. 
The xanthophyll must be further puri¬ 
fied, however, if it is to be used for 
accurate work. 
Xanthophyll takes up ethyl or 
methyl alcohol in crystallizing and 
may be freed of this by precipitating 
from chloroform with petroleum ether. 
Its further purification is completed as 
follows: The crystals of xanthophyll, 
obtained as described above, are care¬ 
fully dissolved in boiling absolute 
methyl alcohol. This is done by plac¬ 
ing the crystals in the alcohol and 
bringing to a boil on the water bath 
for a short time (1 to 5 minutes). 
This solution is filtered by suction to 
remove any undissolved crystals. The 
saturated solution is then placed in the 
ice box over night or longer. The 
crystals will separate in much larger 
plates than before and have an unusu¬ 
ally strong surface luster. They are 
filtered off by suction, washed with low- 
boiling petroleum ether, recrystallized 
a third time, and often a fourth or 
fifth time, from methyl alcohol and 
then dissolved in chloroform. The 
chloroform solution is concentrated by 
suction and warming until xanthophyll 
begins to separate; the solution is then 
warmed to bring all of the material into 
solution and immediately 200 to 400 
c. c. cf redistilled low-boiling petroleum 
ether is added slowly. A yellowish 
