how to test for methanol?


by real
Tags: methanol, test
real
real is offline
#1
Jan2-06, 10:25 PM
P: 20
any simple test to test for the present of methanol?
Phys.Org News Partner Chemistry news on Phys.org
Repeated self-healing now possible in composite materials
Potent, puzzling and (now less) toxic: Team discovers how antifungal drug works
Research offers 'promise' of improved food safety
movies
movies is offline
#2
Jan3-06, 11:26 AM
Sci Advisor
P: 284
Do you have access to NMR or GC? Those would definitely be the fastest methods.
scorpa
scorpa is offline
#3
Jan3-06, 10:33 PM
P: 376
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
ShawnD is offline
#4
Jan4-06, 04:40 AM
Sci Advisor
ShawnD's Avatar
P: 988

how to test for methanol?


Quote Quote by real
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
real is offline
#5
Jan4-06, 04:52 AM
P: 20
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
Monique is offline
#6
Jan4-06, 07:11 AM
Emeritus
Sci Advisor
PF Gold
Monique's Avatar
P: 4,612
Quote Quote by real
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
real is offline
#7
Jan4-06, 05:47 PM
P: 20
but in my school lab, we don't have a GC or NMR. is there other simple test for present of methanol?
Mattara
Mattara is offline
#8
Jan5-06, 12:23 AM
P: 398
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
Jeckel is offline
#9
Sep25-06, 05:54 AM
P: 1
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
BODBOD is offline
#10
Oct8-06, 06:13 AM
P: 1
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
Cesium is offline
#11
Oct8-06, 09:48 AM
P: 274
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
3trQN is offline
#12
Oct8-06, 10:26 AM
P: 349
Did you try using your nose? Its the simplest test i can think of :P
tekvadr
tekvadr is offline
#13
Oct8-06, 07:05 PM
P: 1
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
lapo3399 is offline
#14
Oct8-06, 07:10 PM
P: 56
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
BNC992 is offline
#15
Jul24-07, 07:11 PM
P: 3
Another question about methanol ----->

Where could I take a sample of a "drinking alcohol" to be tested for methanol contamination?
chemisttree
chemisttree is offline
#16
Jul25-07, 01:10 PM
Sci Advisor
HW Helper
PF Gold
chemisttree's Avatar
P: 3,725
Quote Quote by BNC992 View Post
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
BNC992 is offline
#17
Jul25-07, 10:01 PM
P: 3
How long does methanol stay in your system if you accidentaly consume small amounts? (about .10 ml)
gabee
gabee is offline
#18
Jul25-07, 11:27 PM
gabee's Avatar
P: 179
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?


Register to reply

Related Discussions
Thermal Expansion of Methanol Materials & Chemical Engineering 33
Methanol R ? Chemistry 2
Methanol process Biology, Chemistry & Other Homework 1
Methanol Cloud General Astronomy 0
Vinegar to methanol? Chemistry 13