Sciencemadness Discussion Board - how can I recreate the smell of a fart?

how can I recreate the smell of a fart?

whombat - 11-6-2007 at 16:40

No joke folks. I need to come up with a gas that smells as much like a fart as possible for an invention. I am aware of ammonium sulfide, but that won't work. It's too flammable. I need this gas to be put in a small cylinder with a cigerette lighter injector. Can anyone help? any ideas?
Thanks

[Edited on 11-6-2007 by whombat]

chemrox - 11-6-2007 at 17:48

How juvenile!!!

place parafin and sulfur in a test tube and heat the two together. The product is H2S gas, a poison.

12AX7 - 11-6-2007 at 17:49

Hmm... All kinds of aromas. Very complex I'm sure. I'm just groovin' to some right now, myself...

Tim

whombat - 11-6-2007 at 17:51

Thank you for your reply chemrox. As juvenile as it is...is is also BIG business. Therefor, a poison gas will not work either. Can't be killing my customers.

whombat - 11-6-2007 at 17:54

Thanks for the reply Tim and I'm glad I am not sitting next to you!
Seriously, I thought that smart people like yourselfs could help. I am good at business...bad at science. I have tried talking to BOC also, they could only come up with the afore mentioned gas.
I really hope someone can help.

not_important - 11-6-2007 at 17:56

Variable composition, mostly :

hydrogen sulfide, carbonyl sulfide, low molecular weight mercaptans, sulfides and disulfides, C3 through C6 fatty acids, skatole, indole , other amines from decarboxylation of amino acids as well as acids aldehydes from the loss of both NH2 and the carboxylic group.

[Edited on 12-6-2007 by not_important]

whombat - 11-6-2007 at 17:58

Just saw your link there Tim. Thank you. Good stuff.
Damn, I don't know how you guys can understand this stuff!

12AX7 - 11-6-2007 at 18:19

Yeah sorry I can't really be of much help... If there is an untapped million-dollar market for Oude de Flatus, it might be worthwhile to obtain samples of some particular farts (keeping in mind there's a whole wide spectrum, from meal to meal and person to person!) and send them to an odor analysis lab. Gas chromatography and/or mass spectrometry is probably the way to go.

Tim

bereal511 - 11-6-2007 at 19:24

Hmmm, I'm interested to know what your product is exactly, whombat. Never knew that anyone was interested in odors for cigarette lighters.

I'd venture to say skatole might be worth looking into, though I suppose the smell isn't quite right and I'm not too sure if its aromatic (?) properties would be damaged by the flame. Could you give some specifications on the release mechanism of your invention?

evil_lurker - 11-6-2007 at 19:26

1 taco bell bean burritos
1 mcdonalds hamburger, double rehydrated onions
2 deviled eggs
2 beers
1 half cup broccoli and cheese

If that don't make you go "super atomic" then nothing will.

not_important - 11-6-2007 at 21:47

Quote:

Originally posted by 12AX7
Gas chromatography and/or mass spectrometry is probably the way to go.

Tim

It's been done already, that's where I got my list from. If you really want it, the original papers can be tracked down.

Phosphor-ing - 12-6-2007 at 03:39

Whombat you should check out Mythbusters, Episode 48: Franklin's Kite. It shows what is in flatus. I think that would be as good a starting point as any.

whombat - 12-6-2007 at 03:43

not important: You are correct sir! It has been done. Patents prevent me from using the formula. Good Idea on the odor analysis tim!
Sorry Breal...! There is no way I am even going to give a hint of my product to a roomful of geniuses!!! Not without a non- disclosure.

whombat - 12-6-2007 at 03:55

thanks phosphoring...I love that show. I will check it out tonight!

not_important - 12-6-2007 at 05:11

Might be tough to recreate an odor without using anything that makes up the odor. And there's recent patents on this?!? Much research was done for the US space program, over 40 years ago. And there much earlier attempts at analysis as well, less complete because of the low concentration of many compounds.

jimmyboy - 12-6-2007 at 15:46

the paraffin and sulfur will make too much H2S -- besides I think he wants it to be at room temp -- mix ferric sulfide and citric acid -- both nontoxic - and the the resulting gas will be in a pretty low concentration but plenty stinky

bereal511 - 12-6-2007 at 16:09

It's hard to give much advice on what you should be using to produce the odor effect if the specifications for the product are not explained. But I understand, business is business. It's just hard to know what you're looking for, seems like anything that will combust or thermally decompose will be of no use to you.

Ramiel - 12-6-2007 at 16:16

I worked at a minesite with an on-site sulphuric acid plant (which regularly almost killed us all, adorable little thing), and it used H2S in the process. I'd say after testing H2S solutions for months and eating minesite food, that the smell of H2S is different to flatulence. There seems to be a je ne sai quoi in addition to H2S. Scatole would be interesting, I understand that it's used in perfumes.

[Edited on 13-6-2007 by Ramiel]

DerAlte - 13-6-2007 at 18:59

It is indeed, Ramiel. So is indole, almost equally offensive - skatole is beta methyl indole, IIRC. It always used to amuse me that young women, after very carefully bathing, may be undoing some of their effort by using perfume! It's a good job men don't have analytical noses like dogs.

The original question is moot. There are too many varieties of the gas in question...

DerAlte

not_important - 14-6-2007 at 08:14

Quote:

The original question is moot. There are too many varieties of the gas in question...

The ranges of composition are well known, some of the variation is modifying the basic composition and oder, while others are just changing the nature of the carrier gases.

For reasonable healthy humans:

Oxygen 0-10%
Hydrogen 5-35%
Methane 0-30%
Carbon Dioxide 5-50%
Total minor components (listed below) <1%

So 99+ percent is oderless carrier gases, the variations of which don't matter much.

Carboxylic Acids 1-100 ppm butyric, propionic, and valeric are listed as main, C2 to C10 acids were found

Hydrogen Sulfide 0,5-10 ppm

methyl mercaptan 0,05-0,4 ppm
dimethyl sulfide 0,02-0,1 ppm
carbonyl sulfide 0,005-0,01 ppm

indoles 0,5-10 ppm indole and 3-methyl-indolce (skatol) being the major ones

pryrroles less than 10 ppm

Also 0,01-0,1 ppm of other amines, aldehydes, and carboxylic acids formed from amino acids:

RCH(NH2)CO2H => RCH2NH2
RCH(NH2)CO2h => RCHO => RCO2H

Cadaverine is produced from lysine, putrescine from ornithine

Gulping food or drink, or otherwise swallowing air, boosts the amount of nitrogen and may add oxygen. Eating food high in fiber or other non-digestible carbohydrates pushing up the amounts of CO2 and hydrogen, and inbout a third of the population increases the amount of methane (the other 2/3 don't produce methane). Eating food high in proteins increases the amine content, which includes the indoles, and some of the minor carboxylic acids and aldehydes. Food high in organic sulfur increases the amount of hydrogen sulfide and organic sulfides.

And you're not going to recreate the smell without H2S, nor without fairly flammable compounds.

DerAlte - 14-6-2007 at 11:54

A masterly (if not doctoral?) piece of research, not_important !

In the days of my depraved youth, at beer parties as an engineering student, a favorite trick was to practice ignition of the gases, with an over 50% success rate, IIRC. The sulphur compounds then seemed to be oxidized to SO2, a far more acceptable odor. In view of your data, this is hardly surprising.

One wonders where the H2 comes from. It is not a common product of organic degradation. CH4 is easily understood. But there again, biochemistry is quite fascinating and the most remarkable reactions are carried out with ease by various enzymes.

Sulphur compounds, sulphides and mercaptans, and also Indoles, seem to be the key to the odor,

Regards,

DerAlte

Ozone - 14-6-2007 at 17:39

not_important had it right.

You need the fatty acids for the greasy "body", the mercaptans for the "broccoliness" (for this you need ethyl and maybe at trace of propanyl mercaptan, butyl is a dead ringer for skunk, and I've never had a fart like that

). You will also need the old H2S, but a trace of COS would do as well to give it that "egg zing". As for skatole and the like, this is a fart, not a turd; maybe trace, but most of my farts do not seem to have much of a "shit odor".

Free cysteine and methionine are definite components which add to the broccoliness (watch the methionine or your "farts" might smell too much like catfood. mmm.

Maybe a trace of benzaldehyde and phenylacetaldehyde (product of decarboxylation of phenylalanine) would add the "sweetish" smell that seems common to some farts.

I think a trace of ammonia might help too--the aldehydes you get on decarboxylation will react with this (and amino acids) to yield compounds of unknown taste and smell (at least in shit).

I think a good fart is like a good spaghetti sauce--it's much better the second day (after it has reacted and become *one*).

Don't know how to give it the "moistness", which in farts, I think you can (abstractly) smell.

Bless you (if you can sneeze out your soul, could it not be lost farting?),

EDIT: Bummer, the three posts before this one were not there when I submitted this one?!

O3

[Edited on 15-6-2007 by Ozone]

Lambda - 14-6-2007 at 23:55

Why shoot, stab or hit people.

Just use; SMELLY PEPELLANTS and the Mob will ripple apart like Marbles on a table top.
It may however turn out to be rather difficult to make any arrests in this way.

Smelly Repellents:
http://www.riverdeep.net/current/2002/01/011402_smells.jhtml

Chemistry of Skunk Spray:
http://www.humboldt.edu/~wfw2/chemofskunkspray.html

Everything You Wanted To Know About Farts:
http://www2b.abc.net.au/science/k2/stn/archives/archive52/ne...

Here you have some real ass bangers

:

Ask PoopReport: The Smell Of Everyone Else?
http://www.poopreport.com/Ask/Content/others.html

Fun with Feces:
http://www.poopreport.com/Fun/index.html

FACTS ON FARTS:
http://www.heptune.com/farts.html

A compound called "Scatole" is the main component giving rise to the smell of human waste, and compounds called "Fatty Acids" give off a sour smell. I personally find Indole as shitty as it can get, even without Scatole. Scatole and indole with a twitch of Butyl Mercaptan (Butyl Thiol) and Propionic acid will probably make every SHIT LOVER water mouth into a frenzy.

Collecting the gases of rotting cabbage, potatoes, beans etc. and then condensing the gas may turn out to be an easy sources to making your own fart propellant. Or just hire a "professional farter"

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

Bon Appetite,

Lambda.

not_important - 15-6-2007 at 00:15

Quote:

Originally posted by DerAlte
A masterly (if not doctoral?) piece of research, not_important !

Easy - left behind by a space colonization crazy housemate, who dissappeared into the forest years ago.

Quote:

One wonders where the H2 comes from. It is not a common product of organic degradation. CH4 is easily understood. But there again, biochemistry is quite fascinating and the most remarkable reactions are carried out with ease by various enzymes.

Bacterial fermentation, just like in anaerobic sewage treatment. Apparently less than a third of the population hosts the bacteria that convert H2 and CO2 to CH4 and H2O. Carbohydrates feed acid formers, who generate the H2, CO2, and some of the fatty acids.

The indoles concentration is on the borderline of smelling fecal, but not solidly into that range; below 10 ppm the aroma changes into floral. Some of the 'sweetness' may be from them triggering several smells at once. They are less volatile than most of the 'aromatic' compounds, and lag behind in reaching you noise.

[Edited on 15-6-2007 by not_important]

whombat - 15-6-2007 at 15:23

thank you to all! I REALLY appreciate it. Look for mention of this website and all of your help when I launch my product. You will know it when you see it.

12AX7 - 15-6-2007 at 20:41

Quote:

Originally posted by whombat
thank you to all! I REALLY appreciate it. Look for mention of this website and all of your help when I launch my product. You will know it when you see it.

Don't you mean, "you'll know it when you smell it"?

Tim

DerAlte - 15-6-2007 at 22:06

This thread stinks! Amazing how it hangs around....

Interesting how such an apparently trivial subject can gather so many responses. But chemistry involves everything.

not_important, WRT indoles:- the odor of certain flowers are indole based. Personally I dislike them, but most do not. Honeysuckle, gardenia, orange blossom (and mock orange too), jasmine, are a few, (violets I believe also).

My favorite pipe tobacco for blending, Perique (from Louisiana) also has a considerable content of indole. If you sniff it directly, it stinks! But permeating through a polyethylene bag, it smells sweetly of violets. And smoked, it is heavenly...

Whombat, good luck with your invention. Seems there's money even in mephitic odors. But hell, there is in Rap music too so an old fart like me shouldn't be surprised.

Regards,

DerAlte.

eude de human

squizzy - 26-6-2007 at 03:59

It would be affected by what you eat also.
But instead of recreating it why not try isolating the natural aromas from real crap.

There are real processes used in wine making to remove odourants from wine then remove the alcohol and the odourants are then replaced in the low alcohol wine.
This makes it a far more palatable product. In your case theres a surfeit of the natural product. Remove the odour from that and concentrate it.
Perhaps simply entraining it in a solvent or it may be necessary to use low temperature gas condensation techniques to include aromas of higher boiling point.
You might need to blend it to get the morning after a curry experience
Though for my 2c worth seems like a useless product that wastes resources for a trivial humour value Isnt there something useful you could market its not as if there are real problems we need to solve instead of adding to our problems

You asked for it

Nerro - 26-6-2007 at 04:08

Incidentally butanoic acid smells a lot (really a lot!) like manure. Let a potato rot under water in a sealed container and you can pick up quite a hint of butanoic acid.