You can't smell metal

They do indeed get vaporized, its one of the reasons you HAVE to clean your welds on stainless parts (that go into nasty service conditions) because Fe vapor condenses on the plate right next to your weld and will cause corrosion if not removed. Also, when migging aluminium with Mg in it, it will form a black layer of Mg soot if you're not careful about which direction you run your weld.

Clifton Ballad

Very nice project. Did you do / can you do a chromatography test and an IR spectrum on the unknown residue ? The Octen-3-on is a Michael-Acceptor, so it is rather reactive. E.g. those are known to react with thiol groups (e.g. cystein) in your proteins. So maybe it reacted with the dimethylsulfide in your mixture at the higher temperatures of the purification. (Free electron pair of the S attacking the beta-C, forming a C-S+-Bond, concerted electron shift of the double bond to the carbonyl-C, =O -> O-, O- attacking one of the CH3-S+-groups, formation of methoxy-group, charge neutralization and cleavage of the CH3-S-bond.) But the side product has also an intense colour, which points towards conjugated double-bonds. So maybe it's a polymer ?

Dominik Wondrousch

Is there a way for you to activate or enable auto-generated captions for this video in English? The only option right now is auto-generated captions in Dutch :-/ This is an issue for both the Patreon-only and public videos. Thanks.

Ron Painter

Also the metal oxides

Manuel Aparicio-Conde

Lol, my comment on YouTube wasn't a joke, this video prompted me to make a patreon. Just for you lol.

Its interesting because I heard the same thing from other welders. I am really not sure though. Maybe the metal do get vaporized and they are able to react with molecules in your nose and make the smell.

Nile Red

Ok, I'm a welder and i'm not doubting or disputing that the 1-octen is responsible for most of it because it Is so familiar and prevalent between all sorts of metals. I even get that differnet metals would react differently, having encountered most of the common metals as well as more than a few uncommon ones. What I am questioning is what am I smelling when I'm actually welding said metals? Parallel to that would be, how clean would the metal have to be to be able to disregard the 1-octen as the source of odor? I have some parts I've worked on that any oils, including from your hands, are detrimental and require lots of acetone/alcohol and rubber gloves to handle and I could still detect a diferent set of odors for different metals. Aluminium, stainless steel (18Cr,8Ni,balFe) and Titanium all smell different when given the same oil restricted treatment. Titanium has a very distinct smell when ground or sanded as well... As said, I'm just a welder, but Dad was an analytical chemist, so I've picked up a bit about chemistry and understand enough to Not be dangerous... Love the vids, keep up the good work! Clif

Clifton Ballad

Do you ever plan on getting a rotovap for your lab? I don’t think I could ever survive without one!

I said that i didnt like to use it? My only issue is that its not very common so i need to order it

Nile Red

oh yeah, i know what you mean.

Nile Red

damn, thanks! I really appreciate it

Nile Red

ha thanks! I was able to get the set at a really good price.

Nile Red

Thanks!

Nile Red

Absolutely a masterpiece! I really enjoyed your comments and you sharing your thoughts. I really liked how you commented on the progress along the video. Also your editing are really great. One of your best videos for sure!

I loved the reactions of your friends at the end. Fantastic video, I really enjoy you narrating in person along the way, too. This new style is quite good IMO.

Joel

That was a really neat project, I really enjoyed it. One thing I have noticed is that I don't really get that smell when I work on instrument tubing. I assume it is the oxide layer that does it. The BTW, nice bookshelf, I have never seen a complete set of Ullmann's before.

I bet DCM contamination was a big issue here.

Daniel Blake Shoemaker

I assume it's kind of knarly stuff in likely more than one way but why don't you like to use triphenylphosphine dichloride?

Me too, actually. I thought this was going to end up having something to do with ozone, which I strongly associate with metal for some reason. Maybe because of electricity?

I never knew this, I love it. I think having other people in that context is cool, but I don't think I would enjoy having others feature prominently nearly as much as I do the regular format.

Great video Nile, I've always wondered what exactly caused the smell of metal. Thanks for making this video and keep doing the smell videos. Doing one on ozone or a reaction that uses it would be cool, for some reason when I think about the smell of metal the smell of ozone is closely associated.

Kevin Faccenda

Hmm, that very cool but was the loss was due to adding too much DCM? Even if you project failed you have learned a lot from it.

Daniel Blake Shoemaker

Interesting, I never found that source. It does seem to be a decent prep though. Benzaldehyde as a hydride acceptor is also nice.

Nile Red

hmm interesting.. Maybe cooking it destroys a lot of the 1-octen-3-one and other metallic tasting things

Nile Red

Do you have any references for that? from a quick search, I didnt find much

Nile Red

I have never touched DMSO before, so i cant comment on the garlic smell. I have heard of that before though.

Nile Red

Once upon a time in Amsterdam (and Netherlands) you could buy truffles that contained psilocybin but not 'toad stools'. And they were always fresh, never dried. (Today you can get above the ground dried mushrooms but not back then.) Today it's easier, but some years ago not so easy. Some of the "magic" truffles had a "metallic" taste, and I just couldn't get them down easily (with salty peanuts helped) without puking or at least wanting to. That's my story. Mushrooms never tasted metallic to me - not the cooking ones, only the ones from one of the psychedelic 'mushroom stores'.

Lindy

You may want to try squalene as well. It’s a common skin oil that is supposed to contribute to the “metal” smell once catalyzed by a metal.

Neuroskynet

Wow, this is really interesting! I've wondered about this for a long time. Two questions appear: 1) OMG you smelled it with your nose. Something I would never do, at least not right away. I'd have first held it away and done some hand wafting towards my olfactory nerves. 2) You didn't mention blood. It often in the right conditions smells metallic, like iron. I assume for the same reasons? 3) A more general question. Have you touched DMSO? Did you immediately taste garlic or something similar? UPDATE: I wrote this before the very end when you did mention blood. :)

Lindy

How about doing an Oppenauer oxidation? Sounds a lot simpler, and it's the most gentle kind of alcohol-to-ketone oxidation there can be! They've done it here with that very compound: <a href="https://doi.org/10.1016/S0040-4039(01)80985-0" rel="nofollow noopener" target="_blank">https://doi.org/10.1016/S0040-4039(01)80985-0</a>

Gabriel J.

I can tell you that its not a very pleasant perfume, ha

Nile Red

I really needs to get my hands on some 1-octen-3-one to make some perfume. Really loving the smell-related videos.

Simon the Delusional

That is true. Ground metal definitely has a very distinct smell to it.

Nile Red

That is interesting. I do find for me though, that the ketone is way more potent than the alcohol. It would make sense though, that it could be used to identify molds.

Nile Red

hmm, that is very weird. It might be possible that enzymes destroy it. Im not sure though.

Nile Red

It might be possible, but I couldnt find any precedent online.

Nile Red

I think I always did, but I just never really though much about it

Nile Red

That is true. But I didn't want to get into too much detail, because in most cases, when we smell something it isn't as a powder in the air.

Nile Red

Volatility may not be a requirement; a very fine powder that can travel airborne into the nose can have an odor as well, for instance plaster of paris (calcium sulphate) has a distinct odor which I can sometimes also detect from hard water. I can smell sugar as well, but that might actually be slightly volatile.

Kevin Martin

I also find that the smell of hot metal (while grinding, or an unlubricated rubbing surface) is different yet again.

Kevin Martin

I'm pretty sure that I've always found copper and iron to smell different.

Kevin Martin

One more thing I noticed. I mentioned above that for me copper has the most intense smell. But if I take a copper object and handle it for a while until it's very smelly, and then touch it to my lips, the smell disappears almost completely. Even if the part touched with the lips is very small and by far not the whole object (I have a 5cm copper cube that I use for this experiment), the smell is almost completely gone. I then need to handle the cube again for a while to get it to smell again. I don't know how to explain this. Maybe saliva contains a catalyst that destroys the 1-octen-3-one.

Silviu T

Very nice. Thorough science, great lab practice, blind test at the end. I'm very satisfied with this video. Metals do smell, and I knew about the 1-octen-3-one. The smells are different slightly, but for me what differs the most is the intensity of the smell. The odor of copper for me is by far the strongest of all, probably 10 times more intense than the next one which is iron. Zinc smell is very faint. Other metals like aluminum, nickel, chromium don't smell at all. Antimony smells a little less intense than iron, etc. I've never smelled the pure chemical though.

Silviu T

Actually, we can smell octen-3-ol as sensitively as octen-3-one, and the evolutionary reason is that we detect moldy food through it. You can find more information in my answer here: <a href="https://biology.stackexchange.com/questions/58599/what-is-mold-detection-threshold-in-humans/74850" rel="nofollow noopener" target="_blank">https://biology.stackexchange.com/questions/58599/what-is-mold-detection-threshold-in-humans/74850</a>#74850

Great video. Is it possible to use the Jones' reagent or PCC instead to oxidise the alcohol? It's the textbook method anyway

You are right, it's believed that metal has no taste either. It's either the compounds it makes when it contacts your skin, or the slight electrical charge that it generates.

Nile Red

Oh no, I'm sorry to hear that! I went a few months without smell and it was interesting.

Nile Red

Once again, you have managed to nail something new for me and something really interesting! &lt;3 It's also because videos like this, I'm a happy patreon supporter for you. It's actually your fault, that I joined Patreon! ;-)

Alf-Marius Dahl Bysveen

i was always wondering about that :D. But does that also mean that metal doesn't taste of anything? I've heard colleagues talk about a metallic taste after getting an electric shock, so it's probably just something else again correct?

Thorben Zethoff

I have anosmia so I have no sense of smell at all. This is a cool video.

Matthew Wilson