Dear Fafa,

What solvent did you use for extraction?

Please refer to this link

https://www.jove.com/science-education/5501/rotary-evaporation-to-remove-solvent

Regards.

What we did after doing soxhlet we kept the extract in a hot air oven at 70degree for further evaporation 

From 

Shaista jabeen

other alternative is to use a freeze dryer where after cooling the material bellow zero degres centigrades the system is put under vaccum 

Dear Fafa,

  The easiest process to completely dry your extract is:

1. Aqueous extracts: Simply add n-butanol to the aqueous extract which will form azeotrope and make your distillation process faster at 68-70 oC. To completely dry  your extract simply subject the rotavaporised dried extract to lypholiser/freeze dryer to completely dry the extract. Seal with parafilm to avoid further moisture penetration.

2. Alcoholic extract: After you recovered substantial amount of solvent simply dry the extract at 70-80 oC under high vacuum for 1/2-1hr. This removes the bound hydralcoholic solvent. After that dry in vacuum dessicator for 3-4 hrs which will dry it and make it hard rock.

I hope this may help.

Thanks for your responses. In fact I use three solvents ethanol, hexane, and dichloromethane after concentrated the extract with the rotary evaporator I collect the crude with some solvent inside. I have tried the room temperature to evaporate the remaining solvent but it takes days before complete evaporation. is it another ways to dry it quickly ?

I used vacuum drying oven in order to evaporate ethanol from my ethanolic extract. For protection active compounds of extract be sure the vacuum temperature be under 40 degree centigrade.

Use supercritical fluid CO2 extraction, it does not classify water-soluble or oil-soluble ingredients, CO2 is own volatile, CO2 not remain in the sample after supercritical fluid CO2 extraction.( herbal extract temperature be 42 -46 degree )(CO2 is volatile for a short time)(sample will not be oxidized)

There are different types of Rotary Evapotator. The Dry ice model is best, but perhaps you have used the ordinary one. If you have used 95% Methanol or Ethanol, it will be done easily keeping the material in air. But if you used the diluent after dilution in water (say 50% Methanol+ 50% distilled water) , removal of water is very difficult. There is a very less chance of getting the plant materials as dry powder. You may get a paste of materials.

You may try desiccator and/or keeping the materials under Laminar Flow in sterile condition.

Final step get ethanol was the pure ethanol after supercritical fluid extraction herbal use CO2 and 95% ethanol, the pure ethanol contain many the water-soluble and oil-soluble ingredient, GC/MS can direct analysis the pure ethanol, no need to dilution the pure ethanol, if you want to dry the sample, continue CO2 blow off the pure ethanol, CO2 can isolate air for damage ( recommend revise experimental design).

You can not dry the extract thoroughly because the sugar is also extracted during extraction so that the extract can be sticky after removal of the solvent. Is there a way to remove sugars extracted from plants that can be dried?

Which filter was used for filtration process thank you

Dear all,

I support the idea of Intan Soraya Che Sulaiman.

At high temperature the phytochemical constituents of the plant may be damaged. The temperature depends on the plant and solvent used during extraction.

I see the solvents used can evaporate easily after extraction and using a rotary evaporator. Perhaps I would say you don't dry the samples fully (to avoid it sticking on the glass which will force you to use the solvent to recover your extract-if at all you are interested in calculating the yield. Better to remove it when not fully dry and leave it to dry at room temperature, covered with aluminum foil with some holes.