Chemistry of Essential Oils

(Tuis.) #1

N. O. GEAMINE^E 77


ously containing the high boiling constituents left behind in the above-
rectification.
Vetivert oil distilled in Europe has the following characters :—
Specific gravity.1-014 to 1-042
Optical rotation.+ 25° , + 40°
Refractive index.1-5200 1-5230
Acid value. 25 , 65
Ester 10
,, , (after acetylation)...... 130
On fractionation the oil yields results as follows :—


1-5230


65


25


160


Boiling-point at 23 mm.

144° to 164°

164° „ 170°
170° „ 180°

180° „ 185°
185° „ 200°

Per Cent.

8


10


24


30


20


Rotation.

- 4° 10'


- 3° 20'


+ 2° 5'


+ 31° 40'


+ 47° 5'


0-982 to 1-020 (rarely, over 1-050)
ri- 10° to 38°
1-5150 „ 1-5285
4 ,, 20
5 „ 20
lOd „ 150

Vetivert oil distilled in Reunion, or in the Seychelles, has the following
characters :—
Specific gravity. *.
Optical rotation ....
Refractive index....
Acid value ....
Ester „,,...
„ „ (after acetylation )
Oil distilled in the Fiji Islands has a specific gravity 1*018 to 1*0298,
acid value about 30, ester value about 17, and ester value after acetylation
about 145. In all other respects it corresponds with European distilled
oil.
Vetivert oil is soluble in 1 to 3 volumes of 80 per cent, alcohol,
usually becoming cloudy on the addition of more alcohol.
A vetivert oil distilled from roots from the Philippines has been ex-
amined by Eouiv-Bertrand Filsl and found to have the following char-
acters :—
Specific gravity....1-0139
Optical rotationp
Acid value
Ester „
Free alcohols (C 15 H Oj

+ 30n W
21-5
6-5
71-5 per cent.
Seychelles distilled oil agrees generally with Eeunion oil in charac-
ters. It has, however, a lower optical rotation—usually from + 10° to
+ 20°—and a rather lower free alcohol value, the ester value of the acety-
lated oil varying from 100 to 135.
Castor oil and other fatty oils are sometimes used as adulterants.
These oils will raise the ester value, and lower the specific gravity and
refractive index.
The chemistry of vetivert oil is in a somewhat unsettled state,
1
Report, April, 1914.
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