Can Methanol be Detected with TLC?

[real]

any simple test to test for the present of methanol?

 

[movies]

Do you have access to NMR or GC? Those would definitely be the fastest methods.

 

[scorpa]

Are you testing for the presence of methanol in a solution of different compounds or are you testing to see whether a pure sample is methanol or not? If you have a solution of different compounds, assuming they have boiling points that are fairly different you could do a simple distillation, you know the temperature at which methanol boils so if something boils off at that temperature you could assume its methanol and then do a comparative TLC to be sure, or an IR. If you have a pure sample you could do again do a simple co-TLC, or you could do an IR spectra of it...ect.

 

[ShawnD]

any simple test to test for the present of methanol?

Add something like potassium permanganate (condy's crystals) or potassium dichromate. If it makes a horrible smell, it's probably methanol.

 

[real]

i am carrying one experiment on the decomposition of sweetener-Aspartame under acidic condition which will give out methanol
is it easy to test for the present of methanol there by adding potassium permanganate?

 

[Monique]

i am carrying one experiment on the decomposition of sweetener-Aspartame under acidic condition which will give out methanol

do tell us the results! I'd suggest a GC if you have access to one, as a control spike a sample of your solution with some methanol.

 

[real]

but in my school lab, we don't have a GC or NMR. is there other simple test for present of methanol?

 

[Mattara]

I am actually doing that same experiment in school. Try and oxidising it useing pottasium dichromate. This way you should be able to confirm methanol

 

[Jeckel]

My question is on Methonal too

I am trying to figure out a way to tell if there is any contaminates in the Methonal I am currently using? How can I test to make sure I have 100% Methanol?

Also how can I test to make sure I have only Methanol and Di Water and nothing else?

thanks

 

[BODBOD]

I am testing for the absence of all alcohols (mainly methanol, butanol and propanol) within a compound with the exeption of ethanol. Have you any advice?

 

[Cesium]

What other types of compounds are in your solution? Potassium permanganate or potassium dichromate can be used to oxidize alcohols to their carboxylic acids which can be identified by their foul smells. The problem is that you will also oxidize other organic compounds like aldehydes, alkenes, etc.

 

[3trQN]

Did you try using your nose? Its the simplest test i can think of :P

 

[tekvadr]

I want a quick test for the presence of methanol as a contaminate. But since my solution is an experimental ferment, and may also contain ethanol and aldehydes, I assume the suggested use of potassium permanganate or dichromate would not work to show the presence of methanol as an impurity (because ethanol and aldehydes would give similar [false-positive] odors). Correct?

I don't have access to the lab equipment, and I have briefly checked around the winemaking suppliers and have found no quick test procedures or strips, even though methanol is a problem impurity in homemade wine. Along the way, I found this good group and hope for some suggestions; maybe, if all fails, the contact information for an analytical lab that would test a sample?

thanks

mark

 

[lapo3399]

This sounds scary. Methanol is toxic, and acidic conditions can create methanol from aspartame? I hope you mean organic acids, because if you mean HCl, then a lot of people should be dying from drinking diet soft drinks ;).

 

[BNC992]

Another question about methanol ----->

Where could I take a sample of a "drinking alcohol" to be tested for methanol contamination?

 

[chemisttree]

Another question about methanol ----->

Where could I take a sample of a "drinking alcohol" to be tested for methanol contamination?

Where (in the world) are you? In the Yellow Pages look under 'Laboratories-Testing'. Call the labs with the biggest ads first. The smaller guys (with no GC equipment) will outsource your job to the big guys and mark up the price. It may cost you about $100 for the test. About the same price as a VERY excellent bottle of 18 yr old imported scotch. And there will be no methanol there my friend!

Sometimes methanol is added to ethanol to 'denature' it. This renders the drinking alcohol useless (or dangerous) for consumption and so this form of alcohol is not taxed as is most drinking alcohols. It cannot be economically rendered safe to drink. That is the point of adding methanol to drinking alcohol. Better to use the money you will spend on the test(s) to buy a legal bottle (if you are old enough).

 

[BNC992]

How long does methanol stay in your system if you accidentaly consume small amounts? (about .10 ml)

 

[gabee]

That's a worrisome post...I don't know the answer but I would be more concerned about possible damage while it is in your system. From wikipedia:

Methanol is intoxicating but not directly poisonous. It is toxic by its breakdown (toxication) by the enzyme alcohol dehydrogenase in the liver by forming formic acid and formaldehyde which cause blindness by destruction of the optic nerve... If methanol has been ingested, a doctor should be contacted immediately. The usual fatal dose is 100–125 mL (4 fl oz). Toxic effects take hours to start, and effective antidotes can often prevent permanent damage. This is treated using ethanol or fomepizole. Either of these drugs acts to slow down the action of alcohol dehydrogenase on methanol by means of competitive inhibition, so that it is excreted by the kidneys rather than being transformed into toxic metabolites.

I've been wondering how to test for acetone or methanol since it is standard practice at my lab to handle both with latex gloves. I recently read that latex gloves are very permeable to these solvents and shouldn't be used with them, so I was actually wondering yesterday how I could try to test how much methanol or acetone will permeate the glove...I guess it sounds like there's not really a very good way?

 

[Cesium]

I recently read that latex gloves are very permeable to these solvents and shouldn't be used with them, so I was actually wondering yesterday how I could try to test how much methanol or acetone will permeate the glove

For methanol, you can safely wear nitriles, but for acetone the only really resistant glove material I've found is rubber.

 

[Cesium]

How long does methanol stay in your system if you accidentaly consume small amounts? (about .10 ml)

How did you (assuming you did) ingest this amount of methanol? I don't think 0.1mL should pose much of a threat, but I'm not a doctor or anything. Best to call poison control because it'll keep you from having to worry. Blindness can occur at levels lower than the fatal ones stated in gabee's post. The best antidote is probably to drink alcohol (ethanol) because apparently your body can then process in a safer manner.

I've been very scared of ingesting a bit of methanol while boiling solutions of it. Of course I do this outside and try to stay away as much as possible, but it's not the same as a hood.

 

[BNC992]

I did not consume any methanol
I just noticed that common household items have a methanol content, like mouth wash.
Does your liver process it or does it stack up in your system for several months? What happens to the formic acid and formaldehyde that your body makes when it breaks down the methanol?

 

[fedcom]

This sounds scary. Methanol is toxic, and acidic conditions can create methanol from aspartame? I hope you mean organic acids, because if you mean HCl, then a lot of people should be dying from drinking diet soft drinks ;).

A

aspartame does break down into byproducts in the presence of any acid. however the amount of methanol formed is not dangerous to ingest. In fact many fruit drinks have chemicals in them that break down into methanol as well, and an average glass of orange juice has more methanol in it then soda with aspartame.

As for the test for methanol thin layer chromatography might work. I'm not sure if the retention factors for methanol and ethanol are big enough for it to be effective but you might try and look into it

 

[chemisttree]

TLC will be of almost no use to detect methanol. Methanol is more volatile than just about any solvent used to develop the chromatogram and methanol has no chromophore to visualize. Other visualization techniques would be problematic as well.