basic methods of extraction of volatile oils

1. EXTRACTION OF VOLATILE OILS

2. Volatile oil production can be divided into 3 major ways.
1.Distillation
2.Solvent Extraction
3.Mechanical expression

3. 1.Distillation
a) Distillation by water: It is applied to plants which are not
injured upon boiling.
• Crude drug is introduced into the distillation chamber
along with water and subjected to heat below 400 C . A
mixture of oil and water is obtained as a distillate which is
collected in a flask.
• Distillation plant for small amounts in the laboratory we
can do it by using a set made of glass called a “Clevenger
type apparatus”.

4. b) Steam distillation : For substances which are
usually injured by direct heat.
Dried drug ground and covered with layer of
water. Steam is passes through mixture, steam is
generated by another chamber and piped into
container having drug.
The vapour contain vol. oils are introduced in
condensing chamber cooled and collected.

6. 2.Solvent Extraction:
a) solvent extraction
• By soaking the plant in pure solvent.
• Filter the solvent soaked the plant out.
• Evaporative distillation at low temperatures under
pressure.
•The rest of the concrete washed with alcohol several times
to remove other contaminants out.

7. b) Enfleurage method:
is used for extraction of delicate perfumes.
• In this method, layer of fat is spread over a glass plate and
flower petal are placed over fat layer which absorbs v.o .
•The exchausted petals are replaced by fresh petals.
•This process continues till the fatty layer is saturated
volatile principle which are then extracted with lipid solvent
• this process can be done either hot or cold condition.
c) Supercritical Fluid Extraction (SFE)

9. Expression:
Expression can be used with plants such as orange
peel, lemon oil glands. This method does not require heat.
Ecuelle Method
Ecuelle method is used for the extraction of citrus oils
where oils cells in rind are ruptured mechanically using
pointed projections by twisting raw material over them in
clockwise direction either mechanically or manually.