Experiment 15
Study of extraction
process using Soxhlet apparatus
Materials required:
Sample, Round buttomed flask, condenser,
heating mantle, ethanol, thimble, boiling chips
Theory
Extraction is defined as the
process in which the soluble constituents are separated from the insoluble
residue by the treatment of suitable solvents or mixture of solvents.
The soxhlet extraction is the
process of continuous extraction in which the same solvent is circulated though
the extractor several times.
Initially the solvent is
evaporated. Its vapor is carried to the condenser and the condensed liquid is
returned to the drug (packed in thimble) for continuous extraction.
Procedure
·
About 5 gm of sample leaves were cut into small
pieces and were grinded on mortar and pestle.
·
The thimble was filled with this sample.
·
Ethanol was poured into the round buttomed flask
till it is occupied with more than half in volume.
·
3-5 boiling chips (broken porcelain) was added.
·
The round buttomed flask was placed on the
heating mantle.
·
Soxhlet extractor was connected with the flask .
·
Condenser was connected to the extractor and the
apparatus was stabilized using support stand.
·
The heating mantle and the heat was increased
gradually. The solvent was brought only to the vaporization stage but not to a
rolling boil.
·
Heat was adjusted to achieve regular flushing.
·
The extraction was allowed till the colorless
flushing appeared.
·
Heating was switched off and water flow was
stopped once the round buttom flask was cooled down.
·
The extract was collected by evaporating the
solvent on the water bath.
Result:
Hence, extraction was carried out using soxhlet apparatus.
Precautions:
·
Heat sensitive, explosive and inflammable substances
should not be kept near the apparatus.
·
The apparatus should be disassembled only after
the apparatus cools down.
