contineous extraction

Question 1

intro

Answer 1

 It is the type of extraction during which solution of drug, immediately after contact with drug, is
evaporated and vapors are condensed and returned to the drug again.
 Some amount of liquid (solvent) is again and again used to obtain maximum extraction of the drug.
 It is performed by Soxhlet apparatus.

Question 2

apparatus

Answer 2

This apparatus consists of:
o Flask
o Soxhlet extractor
o Reflex condenser

Question 3

process of soxhlet apparatus

Answer 3

 Raw material is placed in a thimble in a central tube of extractor.
 Solvent (extraction agent) is placed in the flask and is heated to reflux in the distillation flask, the
vapors are condensed in the reflux condenser and drop into the chamber containing the thimble with
the material to be extracted.
 The chamber slowly fills with the warm solvent and some of the material is dissolved in the solvent.
 When the Soxhlet chamber is almost full it is automatically emptied by a siphon side arm, with the
solvent running back down to the distillation flask.
 This cycle is repeated several times to enrich the solvent in the distillation flask with the extracted
material.
 A limited amount of hot solvent is made to percolate the drug is order to get concentrated solution.

Question 4

advantages

Answer 4

 Small amount of solvent is used.
 Pure solvent is used to treat the drug ensuring maximum exhaustion.
 Continued extraction can be done to exhaust the complete drug.