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Diethylene glycol in WINE question help please CHEMISTRY gr 12

by aisha
Tags: chemistry, diethylene, glycol, wine
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aisha
#1
Oct7-06, 08:56 PM
P: 587
Hi I don't know where to start in this question can someone please help me out. Diethylene glycol, although toxic, has occasionally, and illegally, been added to wines to enhance the sweet flavour. Propose an experimental design, including the procedure and the equipment that you would use, to remove the diethylene glycol and purify the contaminated wine. Include in your answer any safety precautions needed.

What do I do? How will I know how to remove the diethylene glycol from the wine? Is there another name for this? I think glycol is a common name what is the scietific name?

Someone please help me out! Thanks
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cheechnchong
#2
Oct7-06, 09:53 PM
P: 132
hahha i know this is probably wrong,....baking soda? and maybe in water?
Cesium
#3
Oct7-06, 10:21 PM
P: 274
Diethylene glycol is the name that is commonly used. The systematic name would be something like 2-(2-hydroxyethoxy)ethanol. I don't really know about the purification procedure. Perhaps fractional distillation? Ethanol and water would distill over well before the diethylene glycol (bp is 245C), but I'm sure this wouldn't be the best way to get 100% purity.

mitochondria
#4
Oct8-06, 12:50 AM
P: 5
Diethylene glycol in WINE question help please CHEMISTRY gr 12

Distillation sounds good =p (I'm not sure if it's possible to get 100% purity of *anything* anyway)

Do you need the wine for drinking later =p? Column chromatography may be also be an option. You will probably be able to drink the wine afterwards (but not recommended...)
brewnog
#5
Oct8-06, 06:31 AM
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Sounds like they're pushing you down the distillation route aisha.

Do you understand how fractional distillation works, particularly with regard to boiling points?
aisha
#6
Oct8-06, 12:43 PM
P: 587
Distillation is probably the way to go but I don't know how to do this using boiling points. This looks like the right way to do it because I was reading stuff about alcohols, aldehydes, ethers, ketones, naming these and then their would be a property section where it would talk about boiling points, however I never understood the boiling points. When it said so and so has a high boiling point the number wasn't very high. The boiling point is the temperature at which the substance starts to boil right? I need some help with this one guys!! it's really confusing!
aisha
#7
Oct8-06, 12:46 PM
P: 587
how will I know the boiling point of this alcohol? Diethylene glycol? Will drawing out the structure of this hydrocarbon help? This is a hydrocarbon right? lol
brewnog
#8
Oct8-06, 12:50 PM
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You should be able to look up the boiling point of the substance. Providing it's unique amongst the other constituents of your wine, you can slowly heat the wine, collecting the vapours, and condensing them back into another recepticle. When you've got up to the temperature at which your unwanted substance evaporates, you know to discard it.

Get it?
GCT
#9
Oct8-06, 01:16 PM
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I would prefer the column chromatography over the distillation, also, it would be convenient if you could form some type of a precipitate with the ethylene glycol.
aisha
#10
Oct8-06, 01:46 PM
P: 587
http://en.wikipedia.org/wiki/Fractional_distillation using the apparatus in this link the round flask would have the wine and then i would heat it to the boiling point of the diethylene glycol? then what would vaporize into the other flask? Would one flask have purified wine and the other the diethylene glycol?

I'm not sure how to do column chromatography, but if it is the better method then show me how. However it should involve boiling points because I think that is probably what my teacher is looking for.

Thanks guys for all your help. What would I do without you!
aisha
#11
Oct8-06, 01:50 PM
P: 587
GCT that link you gave me for a tutor looks good, but I don't think they will help me for free.

Does anyone know any tutor sites for chemistry, biology, and math that are free? Something like a chat or something. I know this one ilc.org are there any others??
GCT
#12
Oct9-06, 02:53 PM
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I don't know of any free sites, however, that site that you mentioned during the beginning of the post is mine. If you want personalized help for your project, then, I don't believe that someone out there would attend to your needs for free. However, PF is the best as they come, as far as free help goes. There are tutors at Kasamba.com who can help you through real, live, chat (including me), however the sessions are quite expensive.

Individuals here have given you some very helpful explanations, you can either use column chromatography or perhaps fractional distillation. However, I have never used the latter method with wine; one thing to keep in mind is the question of whether reactions will occur within the wine when it is heated to a certain temperature, so a nice experiment would take into consideration a filtering procedure before the actual distillation or chromatographic stage.
aisha
#13
Oct17-06, 06:17 PM
P: 587
My teacher has said that using the distillation apparatus is a good idea, but can someone tell me a little about how to use it. If we were going to use the apparatus at this site the procedure for purifying the contaminated wine would be to http://images.search.yahoo.com/searc...c32fc&ei=UTF-8

put the wine into the round bottomed flask ? Right?
Then do I need the boiling point of the Diethylene glycol? or the vaporization point?

What will I get in the other flask after I am done? what will be in the place of the water in and water out in that diagram?

Can someone please tell me the procedure for this distillation please
GCT
#14
Oct20-06, 05:46 PM
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First off, you need to have someone supervise you when you are doing the fractional distillation. Basically, you need to monitor the temperature on the thermometer; it is going to change based on which substance is changing its phase. I hope that you recall that when a particular substance changes from liquid to gaseous state, the temperature remains the same during the process because of chemical equilibrium (you may not have been exposed to this specific concept). When the temperature for the gas is that for the bp of your desired substance, then it is participating in a phase transition, which means you better isolate the distillate until the temperature changes again. Again, it would be better if you could separate any particulate matter before the fractional distillation.
old nite
#15
Apr2-09, 11:21 PM
P: 1
u heat the wine and H2O and C2H6O evaporates and the Diethylene glycol is left behid since it boiling point is higher than H20 and C2H6O ( due to intermolecular force)...........



btw u go to LBP cus i got the same question for my HW
epenguin
#16
Apr3-09, 07:43 PM
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Brainstorming - maybe this can suggest better answers?

I suspect there is no solution, that you are only being asked to show some chemical knowledge and thinking. This wine is not so valuable that I can imagine an economically viable process for just removing one component. If there were I doubt you could satisfy the health authorities. Maybe destroying the diol is more important than recovering the rest, the object being to minimise the toxicity when you throw it into a river or waste system? I do not have any very good text and cannot find anything much online I think at least the following is not worse than what has been suggested already.

Because of the vic diol, borate forms a complex with glycol. You could add borate to the wine you distill and that should make the distillation much more specific. Distillation is not destroying the glycol - it's concentrating it.
Adding borate to a chromatography, e.g. ion exchange chromatography, should add specificity. I think borate used to be used in paper chromatography of ribonucleosides, which are glycols (contain -CHOH-CHOH-). However it makes sense to use the borate in immobilised forms, and there are boronate solid supports which are capable of giving very fine separations, even chiral separations - have a glance at these http://www.uni-graz.at/~schmidm/publ...61_269-275.pdf http://books.google.it/books?id=kClX...um=3#PPA216,M1

It sounds too advanced to be the answer sought here, but useful glimpses if you are going into biochemistry.

About the only other well known thing that distinguishes diols from mono-alcohols is oxidation by periodate. See http://www.mhhe.com/physsci/chemistr...vagediols.html . You would have to know something about the conditions for that reaction, e.g. does it happen in fairly dilute aqueous solution? I don't know but I think it does.

Then maybe there exists now some immoblised enzyme system with suitable oxidant to specifically oxidise the glycol - the only small hope of being able to drink it afterwards. I am not recommending that.
Borek
#17
Apr4-09, 04:40 AM
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Necromancy - this is 2006 thread.


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