I am working on phytochemicals extractions. i am a little confused as to how much solvent we should use for the extraction? for example if i have 5 grams of powdered form of a sample then how much solvent i should in Soxhlet Apparatus for the extraction?
Dear Bilal
I agree with the answer given by Alok Nahata. Pl. follow the method advised by him.
Dear Bilal
Agree to Shiv Gupta, Apart from that please note that soxhlet apparatus should be such a size that material should occupy well space. More solvent means more distillation and more deterioration of phytochemicals.
Fatma Aly suppose if i will have powder form of sample which has been ground in coffe grinder. then for 5 grams atleats how much solvent should i take? soxhlet apparatus is about 0.5 liter.
Generally the solvent should be such that it submerges the drug fully in the extractor plus the rbf should have solvent equivalent to at least two complete cycles. So two cycles in the Rbf and one in the extractor. As far as the temperature controls are good, this combination should work perfectly.
The major care with Soxhlet extraction is ensuring that you never run out of solvent in the collection recipient, because if this happens the extract will "fry". So, in my opinion, you should use the minimum volume of solvent that guarantees the previous requirement. I don't know which kind of device you have, but the most recent automated devices allow performing the extractions with minor losses of solvent. If you have an "oldie" than you will surely lost part of the solvent, but even in that case, if you add something about 120% of the Soxhlet extractor capacity, it should be fine (unless you are working with ether...). So, if you have an extractor of 500 mL, adding 600 mL should do the treak. Afterwards, you just need to control the "excess" solvent and eventually add a little bit more. In the last cycle, you should remove the cartridge from the extractor and allow the solvent to evaporate as much as possible, until your extract is nearly dry. In this way, you will save a lot of time in eliminating the remaining solvent, and you will have a "fresh" destilled solvent in the extractor, ready for your next cartridge of sample.
Let's thing "green" ;-)
Dear Bilal Ahmad:
Frequently, I use a volume of solvent that be enough to complete one extraction cycle. To do a efficient extraction with 5 g, you must use an equipment as small as you can.
Dear Bilal
I agree with the answer given by Alok Nahata. Pl. follow the method advised by him.
Dear Bilal Ahmed,
its depends on which solvent are you using for your sample. If you use methanol i will suggest you take 50 ml for 5 gm sample.
you can go through extraction of plant material by increasing polarity of solvent. initially, carried out extraction using hexane or pet. ether for recovery of oil then residue remain will extracted using ethyl acetate, acetone or chloroform as medium polar solvents (100%) then methanol, ethanol (50-70%) or water for extraction of highly polar compounds.
Dear Bilal
I will suggest you that most suitable solvent for extraction is 90%aqueous ethanol and you can use10mlfor 5 gm.sample or solvent should be above of your plant material at least 2 inches in the soxhlet.
While doing extraction, solvent should completely dip the materials. Mostly we use solvent 10x of sample size. For example 5 Lt for 500 gm.
Hello Mr Bilal Ahmed.
At case of Soxhlet extraction procedure, We need to use more than 100 ml of solvent per 10 g of sample. Typically, extraction by Soxhlet requires large solvent volumes.
Salem bilel, if extraction is carried out by soxhlet, whatever was the quantity of plant material (with a volume lesser than the soxhlet capacity), the quantity of solvant should be at least twice the capacity of the soxhlet. Now if the extraction was by maceration the plant material should be just immerged in the solvent if the maceration is triplicated successively. Else, the quantity of solvent should be 5x or 10x the volume of plant material when the maceration was once.
For me it’s difficult to answer to this problem: because the phytochemicals belong to many classes (Alkaloids ; Glycosides; carotenoids ; flavonoids ; essential oil; polyphenolics; Saponins ; Steroids) each works differently . Many methods of extraction vary according to the phytochemicals. The plants are applied in different forms. About the solvents there are many solvents polar and nonpolar and the extraction depend of solubility of component
Normally we use 1:5 ratio for phytochemical analysis, 1 part plant powder means 5 parts solvent. So, I suggest for 5 grams use 25ml solvent.
About 5g of the powdered sample are added to 25 ml of solvent used according to its polarity
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