soxhlet extraction.pptx

Soxhlet extraction is a continuous process of extraction with a hot organic solvent. Typically, Soxhlet extraction is used when the desired compound has a limited solubility in a solvent, and the impurity is insoluble in that solvent.
Soxhlet extraction is a continuous process of extraction with a hot organic solvent.
Typically, Soxhlet extraction is used when the desired compound has a limited solubility in a solvent, and the impurity is insoluble in that solvent.

1. Soxhlet Extraction By: Anupriya Singh                     Ph.D. Scholar              Department of RSBK, Faculty of Ayurveda         Institute of Medical Sciences, Banaras Hindu University

2. Extraction Extraction is the first step in the analysis of plant constituents. 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. The particular method of extraction to be used depends on the: N ature of the constituents Type of the plant material Purpose of the extraction.

3. Soxhlet extraction Soxhlet extraction is a continuous process of extraction with a hot organic solvent. Typically, Soxhlet extraction is used when the desired compound has a  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.

4. Soxhlet extractor A  Soxhlet extractor  is a piece of laboratory apparatus, i nvented in 1879 by Franz von Soxhlet. A Soxhlet extractor has three main sections: A percolator (boiler and reflux) which circulates the solvent. A thimble (usually made of thick filter paper/cotton) which retains the solid to be extracted. A nd a siphon mechanism, which periodically empties the thimble.

5. Assembly T himble: The source material containing the compound to be extracted is placed inside the thimble. The thimble is loaded into the main chamber of the Soxhlet extractor. D istillation flask or Round Bottom Flask (RBF):   The extraction solvent  to be used is placed in a distillation flask. Heating mantle : The flask is placed on the heating element. Reflux condenser: A reflux is placed atop the extractor . Water inlet & outlet : Attached in the inlet & outlet opening of condenser.

6. Working procedure Solid material placed in thimble. Soxhlet extractor is placed onto a flask containing the extraction solvent. Soxhlet equipped with a condenser. The solvent is heated to reflux. The solvent vapour travels up a distillation arm and floods into the chamber housing the thimble of solid. S olid material in chamber slowly fills warm solvent. Desired compound dissolves in the warm solvent. When the Soxhlet chamber is almost full, the chamber is emptied by the siphon . The solvent running back down to the distillation flask.

7. Cont … This cycle may be allowed to repeat many times, over hours or days. During each cycle, a portion of the compound dissolves in the solvent. After many cycles (72 hours) the desired compound is concentrated in the distillation flask. After extraction the solvent is removed, typically by means of a rotary evaporator, yielding the extracted compound. The non-soluble portion of the extracted solid remains in the thimble, and is usually discarded.

8. Advantages It is mechanically gentle on the samples but still efficient in separation. It is able to extract solute from insoluble impurities. It is often used as a benchmark when developing new extraction methods. It allows for unmonitored and unmanaged operation. It is the most useful apparatus for solid-liquid extraction in various fields such as pharmaceutics, environment, foodstuffs etc .

9. Disadvantages L ong operation time required (several hours). Large solvent volumes. E vaporation and concentration needed at the end of the extraction. I nadequacy for thermolabile analytes.

10. Advancement Focused Microwave-assisted Soxhlet Extraction: Microwave-assisted s oxhlet e xtraction is a process in which two sources of energy, namely microwaves (applied on the extraction chamber of a modified Soxhlet) as auxiliary energy to accelerate the process and electrical heating (applied on the distillation flask). Ex. Fat extraction from prefried and fried meat, fish &, bakery products etc.

11. Conclusion Extraction is essential for isolation of different chemical constituent from crude drug material. Extraction depends on properties of material to be extracted.

12. References Harwood, Laurence M.; Moody, Christopher J. (13 Jun 1989).  Experimental organic chemistry: Principles and Practice  (Illustrated ed.).  Wiley-Blackwell . pp.  122–125 .  ISBN   978-0-632-02017-1 . Soxhlet, F. (1879).  "Die gewichtsanalytische Bestimmung des Milchfettes " .  Dingler's Polytechnisches Journal (in German).  232 : 461–465.   Jensen, William B.  (December 2007). "The Origin of the Soxhlet Extractor".  Journal of Chemical Education .  84  (12): 1913–1914.  Bibcode : 2007JChEd..84.1913J .  doi : 10.1021/ed084p1913 . Cumpson , Peter; Sano, Naoko (February 2013). "Stability of reference masses V: UV/ozone treatment of gold and platinum surfaces".  Metrologia .  50  (1): 27–36.  Bibcode : 2013Metro..50...27C .  doi : 10.1088/0026-1394/50/1/27 . The apparatus we propose for the solvent pre-wash is the Soxhlet apparatus, which has been used very successfully before for washing stainless-steel standard-mass surfaces. This apparatus has its main application in chemistry for dissolving weakly soluble species from solid matrices

13. Thank you