Demethylated spirits as solvent

[El Burro]

Demethylated spirits are around 95% ethanol, 4.9% methanol and 0.1% colourant and other additives such as pyridine. The methanol can be boiled off easily but will the other remaining crap cause problems if using it as a solvent for extractions and recrystallisations?

[Hydroponichronic]

Originally Posted by El Burro

Demethylated spirits are around 95% ethanol, 4.9% methanol and 0.1% colourant and other additives such as pyridine. The methanol can be boiled off easily but will the other remaining crap cause problems if using it as a solvent for extractions and recrystallisations?

First off, they're not demethylated, they're just methylated. Second, you can't boil off the methanol. Third, methanol won't crystallize out in any appreciable quantity, so feel free to use this stuff for rxtallization.

[BungHole]

Originally Posted by El Burro

0.1% colourant and other additives such as pyridine.

Yeah, yo crystals ain't gonna be sparklin' white, das fo sho.

Methanol is probably more similar to ethanol than any other solvent, the effect it will have on the properties of the mixture as a solvent is negligible. Take into account the mixture will be slightly more polar, but in that case water should also be a concern. You probably don't want to use it as a reagent though. It's the non-volatile impurities which you should be worried about. Just distill it, and act like the methanol was never even there (with the exception of toxicity risks, don't drink it).

God damn, it's a recrystallization solvent and you're more worried about the impurity with the most similar physical properties to the target compound rather than the other random crap? Crazy ass nigga....

[fcknut]

Yeah, while the methanol can be 'boiled off' if you have a decent fractioanl distillation set-up, the 0.1% of crap is your main issue.

Try cleaning it up with charcoal - either pass it through a charcoal filter (e.g. a water purifier - don't use it for water afterwards...) or stir/boil it up with some activated charcoal and filter through diatomaceous earth.

Might work, might not - try it and report back...

[El Burro]

Originally Posted by fcknut

Yeah, while the methanol can be 'boiled off' if you have a decent fractioanl distillation set-up, the 0.1% of crap is your main issue.

Try cleaning it up with charcoal - either pass it through a charcoal filter (e.g. a water purifier - don't use it for water afterwards...) or stir/boil it up with some activated charcoal and filter through diatomaceous earth.

Might work, might not - try it and report back...

Have a decent hot plate but no condenser + jointware. I could setup a ghetto distillation apparatus with some pots and pans though. In fact thats what I'm gonna do. I've been McGyvering all kinds of shit lately. I McGyvered a vacuum source from a bicycle pump and my latest is a distillation setup. It consists of 2 pots and a lid. 1 small pot goes inside a big pot and a lid is placed upside down on the big pot. Ice is placed on the lid to turn it into a condenser. Not the most effective distillation apparatus but it works. For refluxes I just get rid of the small pot. I'm well acquainted with the proper glassware and equipment but its way more fun improvising everything.

[beaker]

decolorizing carbon might work to remove the dye depending on the chemical properties of the dye like its polarity. Just use a little tiny bit and through it in while boiling the alcohol, reflux it for thirty minutes then filter.

if you are concerned why not go with rubbing compound which is 95%anhydrous ethanol, a little camphor and water, nothing else, if it needs to be anhydrous then treat it with calcium oxide and distill, you'll remove the water and bitter to get pure ethanol.

you can distill out the methanol but you can't just boil it out, you'll need at least a 300mm vigreux with indents to distill a one litre pot, no vacuum for sure.

i've always found that IPA 99% is the best alcohol for xtallizing, it sequesters water very well and in combo with acetone or ether at low temperatures almost nothing will stay soluble in it, it does a good job of extractions too.

to really make any comment on this we need to know what you want to extract, as if we didn't already lol.
what is wrong with using pure methanol? that is easily to get free of impurities.

[El Burro]

Originally Posted by beaker

decolorizing carbon might work to remove the dye depending on the chemical properties of the dye like its polarity. Just use a little tiny bit and through it in while boiling the alcohol, reflux it for thirty minutes then filter.

I could only find activated carbon pills in the pharmacy, not bulk quantities like I was looking for. In this case it won't matter since I don't need much but do pharmacies sell activated charcoal in bulk quantities or do I have to go somewhere else?

Originally Posted by beaker

if you are concerned why not go with rubbing compound which is 95%anhydrous ethanol, a little camphor and water, nothing else, if it needs to be anhydrous then treat it with calcium oxide and distill, you'll remove the water and bitter to get pure ethanol.

I thought rubbing alcohol was IPA. I was talking to the pharmacist today about it though and he says what they call rubbing alcohol in America, they call surgical spirits over here. I remember surgical spirits reeks of something familiar so its probably this camphor containing shit you're talking about.

Originally Posted by beaker

you can distill out the methanol but you can't just boil it out, you'll need at least a 300mm vigreux with indents to distill a one litre pot, no vacuum for sure.

Why can't MeOH be boiled off? Is it an azeotrope or something?

Originally Posted by beaker

i've always found that IPA 99% is the best alcohol for xtallizing, it sequesters water very well and in combo with acetone or ether at low temperatures almost nothing will stay soluble in it, it does a good job of extractions too.

IPA is a complete ripoff in my country. 1L costs 35 euros. Methylated spirits on the other hand is dirt cheap. Once I get a distillation setup, I'll recycle all my solvents so this won't be an issue anymore.

Originally Posted by beaker

to really make any comment on this we need to know what you want to extract, as if we didn't already lol.
what is wrong with using pure methanol? that is easily to get free of impurities.

You probably don't lol. Sodium nitrate. I wanna get some relatively pure NaNO3 and decompose it into NaNO2 so I can produce nitrous acid in situ for Sandmeyers. The ultimate goal is to be able to synthesise azo dyes like methyl orange from scratch but I've a long way to go cuz I doubt I'll find any of the direct precursors OTC. I'm a bit of a fanatic when it comes to making what you can with what you've got cuz I like to think about how my chemistry knowledge will come in if I was in some kinda post apocalyptic, survival type situation. This situation will probably never come but its fun to think about this kinda shit

[kelz 34]

so i have availability to either the methylated spirits which is 95 % approx ethanol and approx 5% methanol with nodoubt other impurities and is only a few dollars per litre, however, i have found a brand of polish vodka that is 95% alchohol - 180 proof and is about 60$ for half a liter, what of the two would i be better to use for an extraction.
I have access to 95% isopropynol, but in the past have had fairly poor results with extraction yeilds, and have tried crystalisation with it and have never had much luck either, i guess that the isopropynol that i used was never anywhere the purity the label suggested.
any ideas

[El Burro]

Originally Posted by kelz 34

so i have availability to either the methylated spirits which is 95 % approx ethanol and approx 5% methanol with nodoubt other impurities and is only a few dollars per litre, however, i have found a brand of polish vodka that is 95% alchohol - 180 proof and is about 60$ for half a liter, what of the two would i be better to use for an extraction.
I have access to 95% isopropynol, but in the past have had fairly poor results with extraction yeilds, and have tried crystalisation with it and have never had much luck either, i guess that the isopropynol that i used was never anywhere the purity the label suggested.
any ideas

180 proof, holy shit. Where do you get that? A bit of activated charcoal removes the colourant from methylated spirits. No idea what else is in there though. They put a foul tasting compound in there in case people aren't deterred by the colour. They often use denatonium benzoate, the most bitter compound known to man.
http://en.wikipedia.org/wiki/Denatonium
Some brands put a bit of pyridine in there.