Hi Abdulelah 

See the attached files above. They have extraction of polyphenols in detail.

Regards 

The purpose is different.

A normal refluxing apparatus consists only of a flask and cooling above (so fumes are collected while boiling and you can keep the amount of solvent constant).

Soxhlet extraction on the other hand is for separating parts that are soluble in a solvent.

on the wikipedia page is a picture of the aparatus:

http://en.wikipedia.org/wiki/Soxhlet_extractor

So there is also a flask that is heated and a cooler above but there is a permeable beaker in between (this contains a [solid] sample). So the liquid that evaporates is collected there, extracts (dissolves) some parts and is then recycled back (this is done e.g. for separating proteins from hydrophobic partsin a biosample). What do you want with the phenols? Is it areaction that you want to do or a separation?

I think an additional question is what is the best solvent to extract phenols. My experience with soxhlet extraction of various factions in organic rich source rocks depended on the solvent ie. chloroform, benzene-methanol and xylene which resulted in different yields of certain organic fractions. The main difference in the apparatus is that sample that you are extracting is not immersed in the heated solvent, rather it is located in a glass microfiber soxhlet thimble placed in the soxhlet glassware above the round bottom which is filled with your solvent. The solvent boils and then condenses into the thimble. Key to note is that the solvent is not heated as it extracts the organics fom your sample. Eventually the thimble reservoir fills to an over flow arm which cyles the extract and solvent back down to the round bottom, and for the solvent to be boiled again. Check for the best solvent as either method would work, but extraction efficiency is more dependendet on solvent.

Normal extractions Vs. Soxhlet Extraction :

Normal extraction :

Impuire solid products or mixture or herbal products containing mixture of chemicals products + suitable solvent in which our desired product is soluble , total mixed in flask and heated at suitable temperature say ex. room temperature to solvent boiling temperature for a particular period , and then filtered, you will get the filtrtrate as solvent + your desired product and top of Buckner funnel you will get undissolved materials .

Thid is a normal extraction.

But here the scientist observed that the product they get was not so much pure.. so Vignesh J Soxhlet in 1879, .

invented a piece of laboratory apparatus or equipment and the process of extraction to get the pure product which was difficult to get in normal extraction That invented piece of laboratory apparatus is called Soxhlet apparatus and process is called as soxhlet Extraction.

see below site for equipment details

http://en.wikipedia.org/wiki/Soxhlet_extractor

Soxhlet Extraction : From Solid impure products , required products extracted with suitable solvent in which it is dissolved, and once it is extracted in solvent , it will not come in contact with the mother impure solid product again, only solvent vapour and solvent again and again extracted the desired product from the mother impure products, so here you will get the more pure product than the normal extraction as other impurities or unwanted material will not come in contact with your extracted product again and again so purity is more,..

see details in :

http://en.wikipedia.org/wiki/Soxhlet_extractor

In soxhlet extraction for each cycle material to be processed get fresh solvent, means the extracted component always in round bottom flask and solvent is vaporized in pure form in soxhlet having additional solubility capability.

I want to extract some plants for fabric printing. which method  is better Soxhlet extraction or extraction by normal refluxing method?

Dear Akram

You may use normal refluxing, as most of the prigments is extracted out by this method.

Because you want to extract polyphenols, I would advise you to use water as a solvent and use a reflux condenser or a thermostatic water bath shaker for extraction. Soxhlet extraction using water as a solvent is not advisable as normally water is available easily as compared to the expensive solvents. In soxhlet extraction, the same solvent is used again and again to extract out the constituents from the crude drug, hence less amount of solvent is used as compared to maceration or percolation etc. For polyphenols, water should be used as they are soluble in water. Yield should not be affected in any case. Only difference would be in the time taken for complete extraction. 

Dear Nida 

PFA some relevant literature for your ready reference

Thank you all for your valuable answers....

Dear all

I want to extract polyphenols from a plant sample by Soxhlet extraction with methanol .

What is the best protocol for Soxhlet extractiont with methanol?

could you suggest the procedure,time required, temperature, weight of the sample and the volume of the solvent ( methanol)?

Thank you in advance

.

Hi Abdulelah 

See the attached files above. They have extraction of polyphenols in detail.

Regards 

click via this website：http://www.creative-bioarray.com/Products/BioBank.htm.

there are expert technical supports in-house helping solve your problems.

Soxhlet extraction is more efficient than normal extraction because same solvent is recycling every time new there which helps in min solvent consumption but everytime new extraction