SOLVENT

EXTRACTI

ON OF

VOLATI

LE O

ILS

DEFINITION OF TERMS

DEFINITION OF TERMSMarc - undissolved residue of the drug

that remains after being subjected to extraction

Menstruum - solvent used

Concretes - an extract of fresh plant parts by the use of a hydrocarbon solvent. It is rich in hydrocarbon soluble materials and devoid of water-soluble components. It is generally a waxy semisolid dark coloured material free from the original solvent

…DEFINITION OF TERMSAbsolutes - an ethanol extract of a

concrete or a resinoid which generally contains the odoriferous components together with very small proportion of colouring matter and is free from any solvent used in the process.

Extractive - product of extraction process

Extraction - The process of isolating essential oil with the help of a volatile solvent

PRINCIPLE OF EXTRACTION

Plant SamplePlant Sample

PRINCIPLE OF EXTRACTION

ChargingEXTRACTOR

Solvent

Volatile Constituents

Waxes

Albuminous matter

Coloring

matter

EVAPORATOR

Concentrated Volatile Constituents

solvent

DISADVANTAGES & ADVANTAGES

DISADVANTAGES

• More complex compared to steam distillation

• Necessitates complicated and expensive apparatus, and a crew of well-trained workers

• Running expenses are comparatively high 

DISADVANTAGES

•  All extracted volatile oils are of more or less dark color because they contain much of the natural plant pigments which are not volatile. Steam distilled oils on the other hand, are in most cases of light color

• Requires greater concentration of alcohol (95 per cent) for complete solution as compared with that in steam distillation

ADVANTAGES OVER OTHER METHODS• Compared with distilled oils the extracted volatile oils,

more truly represent the natural perfume as originally present in the plant material.

• Supreme advantage, i.e., their true-to-nature odor. In addition, certain types of flowers – e.g. jasmine,

tuberose, jonquil, hyacinth, acacia, mimosa and violet – do not yield their volatile oil on steam distillation, and must, therefore, be extracted with solvents.

SOLVENT

SELECTION OF THE SOLVENT

1. Solvent should be selective.

2. It should possess sufficiently low boiling point.

3. Solvent must not dissolve water.

4. Solvent must be chemically inert.

5. Solvent must have uniform boiling point, when evaporated must not leave residue

6. Low price and non flammable

SELECTION OF SOLVENT

highly purified

petroleum ether

benzene (benzol)

CONCLUSION

CONCLUSIONApplication to many

types of plant materialsCarried out in many

countriesTechnically the most

advanced process