Isolation of Curcumin


Isolation of Curcumin from turmeric powder by Soxhlet extraction method.


This is a modified percolation method. This method of extraction is also called Soxhlet extraction due to the specially designed apparatus. It is the process where the same quantity of solvent is made to circulate through the extractor of the drug by evaporation and subsequent condensation.

In this method, the material to be extracted is placed in a “thimble” made of cellulose. The solvent is placed in a round-bottomed flask (RBF), and a reflux condenser is attached above the central sample compartment.

Solvent containing RBF, sample compartment and reflux condenser are separated glassware; which are assembled with appropriate content to make the complete apparatus.

The solvent in the lower container is heated to boil and the vapors pass through the sidearm up into the reflux condenser. Here, the vapor liquefies and drips into the thimble-containing material to be extracted. The condensed liquid gets gradually trickles down the contents of the thimble and extracts its constituents. These extracts increase in level and go to the siphon tube is set up as liquid reaches the point of return, and contents of the extraction chamber are transferred to RBF.

The cycle of solvent evaporation and siphoning back can be continued as many times as possible without changing the solvent, to get efficient extraction. The final extract gets collected in the RBF.


  • A small quantity of solvent is required due to the recycling of solvent.
  • Exhaustive and complete extraction in less time.
  • Good for lab-scale operation.
  • Can be a model for comparison with recent methods of extraction.


  • Not suitable for thermolabile phytoconstituents, as there is continuous heating.
  • Not suitable for large-scale extraction.
  • Not suitable for high boiling point solvent, such as water.
  • Time and energy-consuming as it takes 8,16 or 24 hrs to complete the extraction process.


  1. About 50gm of turmeric powder was extracted with 95% alcohol in Soxhlet assembly until all the coloring, the matter was extracted.
  2. Alcoholic extract was distilled off to a semi-solid brown colored mass (about 4.5%).
  3. The crude extract was dissolved in 50ml of benzene and extracted twice with an equal volume of0.1% sodium hydroxide solution.
  4. Combined the alkaline extracts and acidified with dilute hydrochloric acid. A yellow-colored precipitate was formed. Allowed to settle for about fifteen minutes.
  5. After setting of precipitate, concentrated the extract by boiling on a water bath and at the same time dissolving the precipitate in boiling water. During this process of boiling, the resinous material agglomerated and formed a lumpy mass.
  6.  The solution was filtered in the hot condition and concentrated filtrate to a very small volume. It was set aside for slow precipitation of curcumin which was then dried, kept in a desiccator, and percentage yield was calculated.
Soxhlet Apparatus
Fig. Isolation of Curcumin From Turmeric Powder


 Curcumin was isolated from Turmeric powder by the Soxhlet extraction method.

The percentage yield of Curcumin was 1.96 W/W %.

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