What is the principle of Soxhlet extraction?
A Soxhlet extractor is based upon the principle of a Pythagorean or ‘greedy’ cup – a cup used as a practical joke. Once filled past a certain point, the liquid inside starts to be drained out through a hole in the bottom.
What is the purpose of Soxhlet apparatus?
A soxhlet extractor is a laboratory apparatus for the extraction of lipids and other molecules from a solid sample.
What are the advantages of Soxhlet extraction?

The advantages of the Soxhlet extractor are: simple and clear design, production process continuity, ease of visual monitoring of the process, a low flow of solvent and the possibility of its reuse after stripping and distillation.
Which solvent is used in Soxhlet extraction?
The Soxhlet extraction process heats the solvent (ethanol) to boiling temperature (>78°C). The evaporated ethanol is contained within the apparatus by the condenser unit; however the apparatus should be placed under a fume hood in case of escape.
Can water be used for Soxhlet extraction?
Yes. Water can be used to prepare Aq. extract. But you will have to adjust its temperature knob accordingly as water vaporizes at higher temperatures than methanol or other organic solvents.
What is the difference between Kjeldahl and Soxhlet apparatus?

Soxhlet is a method of extraction of materials from matrix. Kjeldhal is a method of quantification of organic nitrogen. They are not the same, nor do they do the same job. Soxhlet is an physical extractive method for fats while Kjeldahl is a chemical method for % nitrogen in animal feed which is not interchangeable.
What are disadvantages of Soxhlet?
A further disadvantage of Soxhlet extraction is that a concentration/evaporation step is required, and it can introduce a high degree of contamination into the sample with solvent impurities.
Why chloroform is used in Soxhlet extraction?
We therefore decided to compare ether, a standard solvent, with chloroform, which is nonflammable, in Soxhlet extraction. Chloroform was chosen because it is already widely used as a solvent, it is more stable than carbon tetrachloride, and its price per liter is about the same as that of ether.
Why Methanol is used in Soxhlet extraction?
We required more volume of different solvents when we attempt by polarity series. 3. Instead of doing this, directly we can extract the material using methanol as solvent. After concentration, the crude will be fractioned using solvents with increasing polarity.
How do you choose a solvent for Soxhlet extraction?
Popular Answers (1)
- Hexane is the best solvent used to remove oily and fatty materials (Non polar)
- Chloroform/methanol useful for the removal of chlorophyll (slightly polar)
- Ethyl acetate extraction (phenolic compounds)
- Acetone or methanol useful to remove all components (Polar)
What are the major factors which affects the efficiency of Soxhlet extraction?
Besides the type of solvent and its concentration, the solvent:solid ratio, number of extraction steps, pH, time of contact, temperature, and particle size of the solid matrix are also key factors in SLE processes because they affect both the kinetics of phenolics release from the solid structure and the antioxidant …
Is reflux and soxhlet same?
The key difference between reflux and soxhlet extraction is that reflux extraction involves only a flask and cooling above, whereas soxhlet extraction involves a specific apparatus called the soxhlet extractor.