Sohxlet Method

Question 1

Soxhlet extraction

Answer 1

Soxhlet extraction is a chemical processed used to
extract a desired compound from a solid material

Question 2

OIL EXTRACTION

Answer 2

1) Rendering = Used with animal products

2) Mechanical pressing = For oil-bearing seeds and nuts

3) Extracting with volatile solvents

Question 3

Extraction

Answer 3

▶️ It is a process of removing or taking out or separating the chemical constituents from the plant tissues with or without the use of solvents.

▶️ Various methods of extraction are available for this process/extraction.

• Oil obtained by pressing is considered by some to be more natural and superior to solvent-extracted oil, but most commodities vegetable oils, other than palm and olive oil, are solvent extracted

Question 4

The particular method of extraction to be used depends on the:

Answer 4

o Nature of the constituents
o Type of the plant material
o Purpose of the extraction

Question 5

Soxhlet extraction

Answer 5

Soxhlet extraction is a continuous process of extraction with a hot organic solvent

▶️ Typically, Soxhlet extraction is used when the desired compound has limited solubility in a solvent, and the impurity is insoluble in that solvent.

▶️ It allows for unmonitored and unmanaged operation while efficiently recycling a small amount of solvent to dissolve a larger amount of material

Question 6

A Soxhlet extractor has three main sections

Answer 6

 A percolator (boiler and reflux) circulates the solvent.
 A thimble (usually made of thick filter paper/cotton) that retains the solid to be extracted.
 And a siphon mechanism, which periodically empties the thimble

Question 7

Assembly

Answer 7

▶️ Thimble
▶️ Distillation flask or Round Bottom Flask (RBF)
▶️ Heating mantle
▶️ Reflux condenser
▶️ Water inlet & outlet

Question 8

Working procedure of Soxhlet

Answer 8

1) Put solid material in a thimble, which goes into the Soxhlet extractor. The extractor sits on a flask with solvent.

2) Warm up the solvent so it turns into vapor and travels up to the thimble.

3) The compound you want dissolves in the warm solvent, while the stuff you don’t want stays in the thimble.

4) As the solvent fills up with the dissolved compound, it gets siphoned back down to the flask and the process starts again.

6) After a while, the compound you want builds up in the flask.

7) Get rid of the solvent, leaving behind the concentrated compound.

8) The stuff left in the thimble is usually thrown away.

Question 9

SOXHLET APPARATUS

Answer 9

• A Soxhlet extractor is lab equipment designed for processing certain kinds of solids.

• These devices allow for continuous treatment of a sample with a solvent over hours or days to extract compounds of interest.

• Typically, a Soxhlet extraction is only required where the desired compound has a limited solubility in a solvent, and the impurity is insoluble in that solvent.

Question 10

Advantages

Answer 10

▶️ It is mechanically gentle on the samples but still efficient in separation.
▶️ It can extract solute from insoluble impurities.
▶️ It is often used as a benchmark when developing new extraction methods.
▶️ It allows for unmonitored and unmanaged operation

Question 11

Disadvantages

Answer 11

▶️ Long operation time required (several hours).
▶️ Large solvent volumes.