[jdurg]

Hi there.  I have an interesting phenomena going on that I'm hoping someone here has the equipment to help me with.  I picked up my sodium for my element collection a good while ago in 'bulk' quantity.  (I think it was 2 ounces, may have been 1).  Either way, it was a LOT of sodium.  I've 'disposed', hehe, of some of it but still have a lot.  When I got it, the sodium was covered in oxide/hydroxide and was a dull gray -> white color.  I had some high quality mineral oil left over from an earlier lanthanide purchase and put about half of my sodium in there with the typical snap-top vial seen in my periodic table photos.  The rest of the sodium went into a canning jar and filled with some really cheap 'mineral oil' I bought off of E-Bay.  A few months later I went and wrote my article here on sodium and noticed something odd.  The sodium in the canning jar had turned VERY lustrous and metallic and this gelatenous yellow 'gunk' had formed in the jar along with a rancid rotten-fish odor.  I thought this was weird and took some pictures which you can see in the sodium article here at the site.  

A few days ago, I went to check on the sodium again to see if it had turned and saw that all of the pieces in there were now a VERY lustrous and VERY clean metallic color.  The fish-odor is still there in full force, and there's a yellow tinge on everything.  Oddly enough, the gelatenous yellow 'gunk' has solidifed into a soapy mass at the bottom, while a clear layer of what appears to be glycerine is on the top.  I believe that the oxides and whatnot on the surface of the sodium pieces saponified the oil and released some 'impurities' which are causing the yellow color and fish-odor.  Doing a search online I kept coming up with Pyridine or Methylamine when I searched for yellow color and fish-odor.  It's driving me nuts trying to figure out what it is.  

I was wondering if someone here had access to a GC/MS setup, or various other analytical instrumentation for organic compounds.  I have a small vial that I could take some of the yellow gunk and glycerol from the canning jar to send, as well as the initial oil I used which hasn't been in contact with sodium.  I would love to see a Mass-Spectrum of this stuff along with the GC results.  IR Spec might be a good tool as well.  Either way, I want to know why the oil turned this funky color with the nasty smell and why it caused the sodium to turn brighter and cleaner than a piece of platinum.    If somebody is able to help, let me know what needs to be done and I can send it your way and pay for the shipping.  Perhaps an organic-chemistry professor will let you do the analysis for a project or something?  (As the best thing I could ask for would be a comparitive GC/MS analysis of the pre-sodium oil, and the after sodium-oil).  PM me or reply here if you want to/can help out.

[movies]

If the oils did indeed saponify, which I would bet is the case, perhaps you produced some low molecular weight carboxylic acids that are volatile enough to cause the stench.  It could also be some volatile aldehyde compounds.  Butyraldehyde has a smell that would make the strongest among us beg for forgiveness.

[jdurg]

Yeah, I've had the mispleasure of smelling butylaldehyde, butyric acid, and a bunch of other 'butyl' compounds.  Let's just say I stayed away from butter for quite some time.  :p  Whatever this compound is, it's definitely an amine or a pyridine based compound.  The rotted-fish smell is simply unmistakeable.  

[jdurg]

You know, another possibility I never thought of was what if the long fatty-acid chains on the triglyceride molecule had quaternary amines at the end of it?  Perhaps the abundance of the OH group from the oxidized sodium not only cleaved the glycerol end of the triglyceride, but the amine portion as well?  Thus giving rise to trimethylamine which also smells like rotting fish, and may be more possible due to space constraints than a pyridine group.

[movies]

It's possible, I suppose.  I guess I just don't know where nitrogen would come from in this case though.  I didn't think there were any amine residues in mineral oil.