DIFFERENCE BETWEEN VOLATILE OILS AND FIXED OILS

(A) VOLATILE OIL
(i) Volatile at room temp. Usually obtained by distillation.

(ii) Often evaporate and do not leave greasy spot.
(iii) Can not be saponified.
(iv) Complex mixtures of stereoptenes and eleoptenes.
(v) High refractive index.
(vi) Optically active.
(B) FIXED OIL
i. Not volatile at room temp.
ii. They can be obtained by expressional method e.g. butter sunflower oil, soyabean oil.
iii. Leave spot.
iv. Can be saponified.
v. Esters of higher fatty acids with glycerol.
vi. Low refractive index. Optically inactive.