Chemgineer - 18-3-2023 at 14:39
If I do a soxhlet extraction of mint leaves using ethanol it obviously also extracts the chlorophyll and other stuff. Is there an effective way to
isolate the essential oil afterwards?
I've tried steam distillation but seem to get very low (almost none existent) yield.
UC235 - 18-3-2023 at 16:11
Essential oil yields are incredibly low no matter what you do. At most, you can get a few % of the starting material's weight. This is highly
dependent on what part of the plant you're distilling, cultivar, harvest time, weather, etc.
Some strongly scented herbs only contain a fraction of a percent of essential oil. Complicating the matter is nonzero water solubility which leads to
a lot of hydrosol and little essential oil. A receiver that allows you to recycle the lower layer of distillate into the stillpot will improve yield.
You can also saturate the hydrosol with salt and extract with low-boiling organic solvents to recover it.
[Edited on 19-3-2023 by UC235]
Elking_around - 18-3-2023 at 20:21
Following your steam distillation, centrifuging the hydrosol can be an effective way to separate your essential oil from it. You could also try
solvent extraction with DCM I suppose.
[Edited on 19-3-2023 by Elking_around]
Fery - 18-3-2023 at 20:58
There is also a lot of menthol dissolved in water phase. Distill water phase again to obtain more menthol, you can distill off only small part of
water from it which carries most of the dissolved menthol into second distillate.
I always do 2 distillations, first one from big still and in the second one from lab glass RBF.
https://www.sciencemadness.org/whisper/viewthread.php?tid=15...
https://www.sciencemadness.org/whisper/viewthread.php?tid=15...
pneumatician - 2-5-2023 at 09:50
Is the oil rancid??