Originally posted by unionised
I think ozone has mixed up DCM with chloroform.
BTW, XxDaTxX ,
"DMSO is a cheap solvent that you must have access to. Heat some it in your flask, swirl, decant, repeat. Rinse again with water, then tell yourself
"I will never again extract essential oils with DCM. I will do as XxDaTxX says and steam distill before partitioning in DCM."
"
Why?
Quince seems to have cleaned the glassware without using DMSO (and I would have tried caustic first, then white spirit; DMSO isn't that cheap or
accessible it's also a poor solvent for saturated hydrocarbons and a lot of waxes fall into that group). So far as I can judge he's now after cleaning
up the DCM.
Washing the DCM with caustic to remove the waxy stuff might work but alkaline extractions often give messy emulsions.
For the original extraction of the oils, in general it's better to steam distill out essential oils, not least because water's a very cheap solvent.
OTOH the oils always come over with a lot of water and you will improve the yeild if, in addition to simply separating the oil from the water by
density, you also extract the water layer with a solvent to remove such oil as is dissolved in it. DCM is quite a good choice for this as it's easy to
evaporate off again later.
Oh, also, I wouldn't have refered to the DCM/water azeotrope if it didn't exist and I'm reasonably familliar with the idea of steam stripping for
solvent revovery. I still think it's a weird steam distillation.
I still want to know what this thickening agent/wax that distills below 40C is. Whatever it might be, if it distills over with straight DCM at 39.75C
I suspect it will distill over with the water/ DCM azeotrope at 38.1C so I don't see any advantage to steam distillation to clean up the solvent
(unless the stuff happens to react with water). |