freddurgan - 28-9-2006 at 17:39
Like Canola oil or something like that? All I want to do is remove unwanted nonpolar stuff from my already extracted aqueous acid solution.
IPN - 28-9-2006 at 23:52
You'll just get a big mess with cooking oil. Use something like naphta, pet. ether, Toluene or xylene.
not_important - 29-9-2006 at 00:10
I think you should have posted this as a continuation of your earlier question, it really needs the background.
Oils are not fully non-polar, the triglyceride section has some polarity. Worse than that, they are a bit reactive with hydrolysis and
transesterfication being possible although short contact times would generally avoid the problem.
The natural triglycerides are somewhat viscous, which is not desirable in a solvent as it slows down both the diffusion of the solute and the
separaion of the two solvent layers. Oils also have a bit of a tendency to form emulsions, again making it more difficult to separate the layers.
As you just want to extract unwanted junk, the non-volatility of vegetable oils isn't much of a problem for your case. However they are harder to
clean up after.
A standard hydrocarbon solvent, such as the common "VM & P Naphtha", should work. Wash it with water once, just to remove any proprietary stuff
that might be in the particular brand you find. Remember that naphtha/petroleum ether burns nicely - no flames, good ventilation.
If you are a good modern chemist, you'll save the used solvent for eventual distillation to reclaim much of it. As a minimum, don't pour it down a
drain, least horribly deformed tadpoles, NY albino alligators, and wolf-sized sewer rats hunt you down.
freddurgan - 29-9-2006 at 18:14
I have three choices after some research:
VM & P Naptha
Xylol (Xylene. unknown concentration)
Toluene (container says "100% Pure")
What would you use?
not_important - 29-9-2006 at 20:38
Depends one exactly what is being worked with. The aromatics, xylene and toluene, are slightly better solvents for 'typical' organics that the mostly
to purely alkanes of VM&P. This can be good or bad. In your case simply picking the least expensive might be best.
For simply pulling out junk, they should work as is. A simple safety measure is to do a water extraction on them before use; that way anything in them
that might end up in your aqueous layer will be removed.
If you were using them to extract something wanted from a water solution, then I would give which ever one was used a distillation. Watch the
temperature range, don't take the flask to dryness - not just for the normal reasons but also because you want to leave behind any high boiling
components that could be annoying to remove from your desired material. You want the lower boiling part of the solvent.
If you can safely distill flammables, then another option is automotive fuel or stove fuel of the "white gas" type. Depending on where you live, these
may be cheaper than the store solvents. But you will want to distill those to collect cuts that boil over specific temperature ranges, and to leave
behind the higher boiling portion.