Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: simmis_sim88 on 05/03/2006 20:36:11

Title: How do you make an ester that smells of vomit?
Post by: simmis_sim88 on 05/03/2006 20:36:11

So i have read the previous post that
butanoic acid gives vomit its distinct smell.

but what i really need here is to recreate a vomit ester - i saw my teacher do it last yr, but he wouldnt tell us the chemicals he mixed tog.  he jus showed us the resultant clear solution and let us smell it.

it smelt so bad.

so does anyone know how to make an ester that smells like vomit>>>>

-jordan

Title: How do you make an ester that smells of vomit?
Post by: chris on 05/07/2008 23:06:27

I'd suggest it's something like ethyl butanoate, since this would be the esterification of butanoic acid and ethanol.

Chris

Title: How do you make an ester that smells of vomit?
Post by: Bored chemist on 06/07/2008 13:37:26

Ethyl butanoate smells nice, it's like pineapple or orange. It only smells like vomit if you have been eating a lot of pineapples before vomiting.
I doubt there's an ester that smells like puke but butanoic acid is pretty unpleasant.

Title: How do you make an ester that smells of vomit?
Post by: chris on 07/07/2008 15:20:03

Thanks BC; butanoate definitely smells like puke - very unpleasant! I'd not realised that ethyl butanoate smells like pineapple - that sounds nice! What about butyl ethanoate? Anyone know what that smells like?

Chris

Title: How do you make an ester that smells of vomit?
Post by: RD on 07/07/2008 15:44:45

Quote

Butyric acid, for instance, has a strong odour like that of rancid butter (of which it is an ingredient) and is a component of what we normally call body odour...

Ethyl butyrate and methyl butyrate, however, which are the esters of butyric acid, smell like pineapple and apple, respectively.

http://innovation.dc-uoit.ca/todds/orgn/week13/Lab08.pdf

Title: How do you make an ester that smells of vomit?
Post by: chris on 08/07/2008 08:27:17

Great, that's ethyl butyrate taken care of, but what about butyl ethanoate?

Title: How do you make an ester that smells of vomit?
Post by: cconley on 11/07/2008 20:06:38

Not sure about the butyl ethanoate.

A common mistake is that too much butanoic acid is used while making esters, so even though you may make a pleasant (fruity) smelling ester, the excess material still smells horrible, and overwhelms the product.

This could be doubly true if you use a foul smelling alcohol, such as octanol (used to imitate the smell of human sweat in mosquito traps).

My guess is that the teacher did not make an ester that smelled like vomit, but mixed some foul chemicals together that lingered after the chemical reactions.

-Chris: CT, USA

Title: How do you make an ester that smells of vomit?
Post by: blakestyger on 15/07/2008 20:21:44

I remember learning that butyrates are the main components of the smell when human sweat gets stale as it's quite odourless when fresh.

Has anyone noticed how really rank unwashed shirts can smell exactly like the spice cumin?

Title: How do you make an ester that smells of vomit?
Post by: DonBrown on 12/08/2008 18:10:56

I think(?) I recall many years ago producing such a smell when boiling a mixture of glycerol and dilute sulphuric acid.  I can't remember why we were doing it, but it sticks in my memory because of the smell.
Of course after 40 odd years, it may be that my memory is wrong (about the mixture) - especially as I can't recall the context.