Sciencemadness Discussion Board

Science of Vomit

mericad193724 - 6-8-2006 at 19:27

Hello,

I am going to be talking about vomit from a chemistry/science perspective. I am sure we have all "emesised"(vomited) and therefore I am sure you are familiar with that characteristic strong smell of the vomit.

Vomit is the expelled contents of the stomach and the stomach contains dilute hydrochloric acid, bacteria and enzymes (IIRC Pepsin).

If I wanted to reproduce this odor would it just be as simple as mashing up some spaghetti and adding it to hydrochloric acid (maybe concentrating this mush to get a smelly concentrate.)

Is the smell the action of hydrochloric acid, bacteria, enzymes, or something else???

Is it possible to try to create this smell liquid and concentrate it...just for fun :D.

(This topic is sort of on the edge and I am trying to be serious so I hope it doesn't go to Detritus)

Mericad

chemoleo - 6-8-2006 at 19:53

Butyric acid is well-known to smell like vomit, it seems likely this is also what you puke up (next to other goodies).
Quote:
It is notably found in rancid butter, parmesan cheese, and vomit, and has an unpleasant odor and acrid taste, with a sweetish aftertaste (similar to ether). Butyric acid can be detected by mammals with good scent detection abilities (e.g., dogs) at 10 ppb, while humans can detect it in concentrations above 10 ppm.


http://en.wikipedia.org/wiki/Butyric_acid

I suppose it could be made through bacterial processes in the gut. Its bacterial precursor can be acetone. I seem to remember something that if you are seriously sick by some stomach bug, one develops an 'acetone breath'.

Then let's not forget bile, which, although secreted into the small intestine, probably reenters the stomach to a small extent. However, judging by its contents (http://en.wikipedia.org/wiki/Bile) it doesn't contain particularly smelly things.

Organikum - 6-8-2006 at 20:17

Butyric acid is what makes you want to vomit and thats what you are after and guess what? Butter. And common sense or just humidity.

But so we are at it: Feces! Now thats me some interesting indoles!

ethan_c - 7-8-2006 at 00:29

I was always told that the stomach contains very corrosive and concentrated acids. Now that I've actually had some experience with chemistry, I very much doubt that the hydrochloric in our tummies could hold a candle to any stronger, lab-grade stuff (let alone fully concentrated).
It would be interesting to do a titration and find out. One should obtain stomach fluid through the usual method (ipecac if no warm, humid, open air staph-laden salad bars are around), probably centrifuge it at high speed (>5,000RPM) for a fair amount of time to pull out all the chunks and debris, hopefully leaving a somewhat clear solution, and perform a standard titration with NaOH.

At the end of AP Chemistry, we got to play around and make whatever we felt like. Some of the girls decided to try and make some esters and ended up spilling several mL of butyric acid on the carpet. I felt SO bad for the next class…and the class after that, and the class after that…

mericad193724 - 7-8-2006 at 06:21

Butyric acid...that's it!

I would like to try to make some. I found a synthesis for isobutyric acid in one of the library books we have. Butyric acid is VERY similar, they just have different structures. This synthesis involves materials that can be easily be found!

Isobutyric acid is supposedly bad smelling, but n-butyric is worse. Is there a way to convert isobutyric acid to n-butyric acid???

This synthesis is pretty simple fro isobutyric acid:

Place a mixture of 50 g. of isobutyl alcohol and a solution of 15 g. of
sodium carbonate in 150 ml. of water in a 4-litre round-bottomed flask.
Add a solution of 140 g. of potassium permanganate in 2750 ml. of water,
with vigorous stirring, during 3-4 hours. Continue the stirring and cool
the mixture to 4-5° by immersion in a bath of ice water. Allow the
reaction mixture to attain room temperature gradually. After 12 hours,
filter off (or, preferably, centrifuge) the precipitated manganese dioxide,
evaporate the filtrate on a water bath to about 150 ml., and then cool.
Cover the solution with a layer of ether and acidify with dilute sulphuric
acid. Separate the ether layer and extract the aqueous layer two or
three times with 50 ml. portions of ether. Dry the combined ethereal
extracts over anhydrous sodium or magnesium sulphate, remove the ether
on a water bath, and fractionate the residual liquid. Collect the isobutyric
acid at 153-155°. The yield is 45 g.

Any way to convert to regular Butyric Acid?

thanks

Mericad

DeAdFX - 7-8-2006 at 07:12

Before the summer started I wanted to Isolate the enzyme Urease from soybeans. In order to isolate the enzyme I used acetone/water solution. Long story short.... I forgot to dump the left over acetone solution/soybean goop and after a week there was a really bad smell[a mixture of vomit and mostly anus]. The goop also had the consistancy of vomit/ looked like vomit.

YT2095 - 7-8-2006 at 07:39

it may be worth looking up Bile salts also, I`m fairly sure it has something to do with Cholesterol too.

maybe that`s where the Butyric acid comes in?

but yes, Bile has the main characteristic whiff of the Technicolor Yawn :)

12AX7 - 7-8-2006 at 15:17

Quote:
Originally posted by mericad193724
Isobutyric acid is supposedly bad smelling, but n-butyric is worse. Is there a way to convert isobutyric acid to n-butyric acid???


Not really.
Quote:
Place a mixture of 50 g. of isobutyl alcohol and . . .


Try n-butyl instead. Wikipedia says KMnO4 oxidizes butyric to CO2, so a somewhat more mild oxidizer may be a good idea.

Tim

not_important - 7-8-2006 at 15:37

I'll try to find and get a scan of one, but several late 19th and early 20th century org chem books had a biological route to butyric. A thumbnail description is

make a solution of common sugar, add some 'spoilt milk' - I suspect that acidophilus milk or plain yogurt would.

let it start fermenting, and chalk powder to control the pH.

after some days it will be a mush of calcium lactate crystals. Now add old, rotten cheese (again, a type of cheese that naturally contains butyric fermenting bacteria would work)

again over several days the lactate crystals dissapear as they are converted into butyrate.


The nice thing about this route is you could save some of the calcium lactate and acidify it to get lactic acid, which would add a sour milk smell to the butyric acid.

I remember reading that there were small amounts of iso-butyric and acetic acids as well, lactic acid and traces of ethanol also occur.

ethan_c - 7-8-2006 at 15:49

Quote:
Originally posted by mericad193724
Butyric acid...that's it!
I would like to try to make some.


Why?? You have no IDEA how bad it smells until you actually encounter some. Yeesh. It just hangs in the air even after any actual material is long gone.

chemoleo - 7-8-2006 at 16:30

Please, for the preparation of butyric acid let's generate a fresh thread. I don't think it'd be appropriate nor easy to find with a search engine under the heading 'science of vomit'.

I'll happily split posts into that new thread if it becomes necessary.

Vitus_Verdegast - 7-8-2006 at 22:51

Quote:

But so we are at it: Feces! Now thats me some interesting indoles!


Does anyone have more information on this matter? I've once heard that the Homo sapiens excretes several grammes of indole a day via the feces.

Now if this could be extracted and purified, then making tryptamines could not be made more OTC :P
Quote:

it may be worth looking up Bile salts also, I`m fairly sure it has something to do with Cholesterol too.


Cholesterol is soluble in an aqueous solution of bile salts IIRC.

mericad193724 - 8-8-2006 at 07:17

Continuation of this thread with will now focus on the synthesis or extraction of butyric acid and/or a similar bad smelling compound

The new thread is located in Organic chemistry - title is "Butyric Acid - Synthesis/Extraction"

Mericad

Vitus_Verdegast - 8-8-2006 at 08:12

Just a final note on indole in feces:

I looked into J. Biol. Chem. 32, 17 (1917) today, "The determination of fecal indole" by Olaf Bergeim, and I'm afraid that feces can be considered a very bad source for extraction, as it seems that 40 g of fresh fecal matter of high solid content contains a mere 0.5mg of indole :(