Sciencemadness Discussion Board

Distilling listerine....

evil_lurker - 29-11-2005 at 12:28

Well I decided to take my distillation setup thats been collecting dust and take it on its virgin run.

Knowing me, I couldn't do it the easy way and just practice on some inoccuous substance such as water, I had to go off and do something semi complicated.

So I decided to try and distill some listerine to get some technical grade alcohol free from methanol. Listerine seemed like a good choice since the starting concentration is 26.9%.

Walmart had the generic nasty brown original flavored stuff on sale for $1.97 for 1.5 liters, which boils down to about 400 mls max theoretical yield.

I figured Everclear is cheaper in the long run but at least this will give me some experience.

So I filled up a 2 liter flask with 1 liter of Listerine set up for simple distillation and cranked up the hot plate full blast. It sat and sat and sat and did not boil. Finally it got to boiling and to my surprise the temp shot up all of a sudden and the alcohol started coming over at 85C degrees.

That kinda took me by surprise, but I can understand because of the other stuff in the mix.

The temp stayed at 85C for a while and slowly crept up to about 90C after about 250 ml came over. This was set aside and the distillation continued.

I was rather expecting to see the temp stabilize at some point, then shoot up, but it just slowly kept on creeping up to 100C

I distilled about another 100 ml from 90C to 95C which caught fire and burned pretty easy not leaving much water left.

After 95C the stuff got hard to light and distillation was discontinued at 97C, the last bit of distillate saved and added to next liter batch to be distilled.

Anyways quite the learning experience and I still got a lot of distilling to go. Will keep everyone informed of the results.

runlabrun - 29-11-2005 at 19:41

The point of this thread is what exactly? You have told us the temps of fractions in listerine... what are the fractions? listerine has ethanol, mint flavouring and some kind of a disinfectant doesnt it?

Why are we talking about fractions of listerine?

-rlr

Magpie - 29-11-2005 at 20:30

Even if you had top grade vodka, i.e., water + ethanol, you would not just step change to the ethanol bp and then to the water bp. To get step changes like that you need a fractional distillation column (I'm assuming you didn't use one). Also, ethanol forms an azeotrope with water at about 96 wt% alcohol so this further alters the bp.

I commend you for getting out your equipment and firing it up. Good glassware should not be left dormant. ;)
This is also, I'm finding, typical of the challenges facing the home chemist using OTC reactants. You just never know what that extraneous shit they put in is going to do to your results. :o Actually, in the end, I think we will learn to be better chemists for these challenges.

evil_lurker - 30-11-2005 at 04:42

The point of this thread is twofold, to evaluate a potential source for an OTC reagent for those that cannot purchase pure alcohol and to expose any pitfalls encountered along the way.

I managed to collect about 950 ml of distillate from the original 3 L of starting product.

Upon burning it leaves a watery milky residue with a slightly tan color of unknown composition.

My guess is that the crude product contains benzoic acid and god knows what else that was distilled over.

I'm going to try to neutralize it with a bit of sodium carbonate, redistill the product, treat with Na2SO4, then distill once again and see if that works.

sparkgap - 30-11-2005 at 06:20

From here:
Quote:

Active ingredients:

Eucalyptol 0.092%
Menthol 0.042%
Methyl salicylate 0.060%
Thymol 0.064%

Inactive ingredients:
water, alcohol (26.9%), benzoic acid, poloxamer 407, sodium benzoate, caramel


So you'd expect ~800 mL of alcohol as distillate from the original 3 L, with some water forming an azeotrope with the alcohol. The tan color is most likely due to the caramel.

sparky (~_~)

Douchermann - 30-11-2005 at 15:28

You could do other stuff with the listerine. Try to extract the Eucalyptol and Methyl Salicylate or something. Eucalyptol is a liquid and it comes off at about 176C. Methyl Salicylate is also a liquid but it boils off at 222C. The problem is the menthol in there boils at 212 C and its a solid. It would jam up your condenser before you could distill any Methyl Salicylate over (That stuff is cool because it is fluorescent). If you wanted to you could distill off the Eucalyptol, then make a re-sublimation type setup (except it technically wont be sublimating) to collect the menthol and the distill the Methyl Salicylate.... in fact I think I'm going to grab myself a couple liters of listering next time I'm at walmart.

Edit: I can't seem to find any chemical information on 'poloxamer 407' does anyone know anything about this chemical?

[Edited on 30-11-2005 by Douchermann]

sparkgap - 30-11-2005 at 22:57

Poloxamer 407 is a block copolymer of oxirane (ethylene oxide) and 2-methyloxirane (propylene oxide) used in Listerine as a surfactant of sorts, helping the active ingredients clean the mouth.

I don't really think it's worth the trouble to attempt to isolate the other stuff 'cause they comprise only a measly milliliters of the Listerine.

sparky (^_^)

Douchermann - 1-12-2005 at 13:22

True. I would do it, but thats just me. In a liter of listerine there is about 92mls of eucalyptol (you can see the obvious correlation between this and the other values, I should not need to tell the rest of them). If you were really desperate for eucalyptol or even the other ingredients you could just buy cheap listerine on sale and get alcohol and 4 active ingredients (provided you have the aparatus to do the extractions) for a very cheap price. Eucalyptol (I'm just using this one because its the easiest to extract out of the 4 other ingredients) runs about $95 for 500mls (www.sciencelab.com) which would take about 5.5 liters of listering to make that much. If you can buy listerine at the price prevously listed thats about $7.22 for all that. Plus you get about a liter and a half of ethanol, 231 grams of menthol, 330ml of methyl salicylate, and 352 grams of thymol. That looks pretty good IMHO

neutrino - 1-12-2005 at 14:27

You are off by a few decimal places:

0.092% * 1000mL = .92mL

Douchermann - 1-12-2005 at 17:13

Whoops, sorry, I was treating the percent as if it was already converted to the decimal value for 9.2 percent. Hahaha, then it is pretty useless to try to extract that stuff.

Magpie - 1-12-2005 at 19:02

One can steam distill eucalyptol along with camphor from sagebrush if this plant is available to you. Probably not in Illinois I'm guessing.

Douchermann - 2-12-2005 at 04:46

Yeah, sagebrush only grows in the mid-columbian but thank you.

Reflux

MadHatter - 2-12-2005 at 10:35

evil_lurker, are you using a reflux setup ? The temperature in the reflux column will be ~78C
when the ethanol fraction comes over. Also, the generic "Listerine" can be bought at
Dollar General for about $1 a litre.


[Edited on 2-12-2005 by MadHatter]

evil_lurker - 4-12-2005 at 13:28

Unfortnatly I am without a good fractionating setup. I posted another thread on use and columns but there is no real info there.

Basically I think the gist of things is I'm just gonna have to get a Hempel column and do some experimenting.

water bath?

quantumcorespacealchemyst - 3-12-2014 at 21:53

i have used a water bath with a round bottom flask and adaptors that make a sort of column and wrapped some foil around the flask and the adapters and the first half of a bend adaptor.

using about 111ml of generic equate (compare to listerine), about 20 plus ml distilled over before slowing significantly, to a near stop. i turned it off and the mintyness has distilled over. the bath was water and even though there was some borax in it (saved some borax in water and diluted it), the temperature doesn't seem likely to have reached the stated boiling point of the above stated compounds.

i am using this specific bit to dissolve stuff from an ether extraction (which was recollected and the flask used after distilling to collect the ethanol distillate) for a tincture.

and while the taste (testing about 1.4ml) is good, i am unsure about how the compounds distilled over (azeotropes?). this stuff is expected i suppose as theory and experiment are not always congruent.

the last bit that is an unknown is if the polaxomer 407 being "a block copolymer of oxirane (ethylene oxide) and 2-methyloxirane (propylene oxide)" is toxic to ingest, if it turns to ethylene oxide in the body (and propylene oxide), if it distills over anyway (the menthol sure seems to have), and if under normal circumstances if this polaxomer 407 is absorbing through normal use of mouthwash sublingually (being that ethelene oxide is supposedly harmful to a great degree).

please inform me about this stuff
i wonder what the side reactions are, if making ether with it using H2SO4 and if benzoic acid acts like benzene to any degree when distilling, helping to keep water out.

i guess it may be similar to steam distillation where the other stuff hitches a ride with the ethanol the way say cinnamaldehyde does with water in steam distillation. hopefully the poloxomer doesn't

edit: i guess it is not what i thought, http://en.wikipedia.org/wiki/Poloxamer_407, i believe this stuff is still in the flask, there was foaming up, probably caused by it, and it didn't reach up through the pipe works and i assume it wasn't made harmful by slight heat in the presence of benzoic acid or the other components.

i don't understand about the thymol, eucalyptol, menthol, and the methyl salicylate, coming over, maybe reduced pressure will help? they are still volatiles i believe.

edit: i guess not, about the benzoic acid

[Edited on 4-12-2014 by quantumcorespacealchemyst]

smaerd - 4-12-2014 at 13:45

I did a fractional distillation of a knockoff mouthwash brand to try and get some quick ethanol. It was tainted with flavoring/aroma ingredients after two passes with a vigreux column. I don't have the temperatures that I collected the fractions at unfortunately. The polymer/surfactant does indeed remain in the flask. Might be a decent way to get some minty grain alcohol or something but for lab purposes I abandoned it. Think I used it to clean my bathroom mirror.

Maybe with more careful distillation the eucalyptol, menthol, etc, could be removed but I didn't fuss with it. I recall trying to filter the solution through fish-tank grade activated carbon to try and sequester some of the non-polars before the second pass without any noticeable effect.

subsecret - 4-12-2014 at 17:06

This might be a little off-topic, but has anyone tried distilling hand sanitizer? It's about 60% ethanol, but it's gelled. Maybe you could add water to make it less viscous. All other ingredients have high boiling points, with the exception of fragrance, which some hand sanitizers contain.

macckone - 4-12-2014 at 22:31

Eucalyptol, Menthol, and Thymol are part of SDA-37 denaturant formula.
It is designed to be next to impossible to remove this combination from
ethanol. That isn't to say impossible but very close.

Hand sanitizer is going to have a denaturant as well.