Sciencemadness Discussion Board

What on earth is my "Pyridine"?!

ChocolateStirBar - 10-12-2017 at 11:48

I bought what I assumed was pyridine a while ago alongside some other common solvents. It wasn't long until my lab started to smell very sweet and ethereal, which I put down to being either the diethyl ether or the THF.

The THF was an amber glass bottle packaged next to the "pyridine" which was in a HDPE bottle, so I assumed the odour was coming from the THF. Having transferred said "pyridine" to a reagent bottle, it is absolutely the source of the sweet smell. Now...absolutely everything I read is telling me that this is NOT pyridine, as no smell of burnt coffee, nor fishy stench is detectable. Simply an ethereal sweetish smell which seems very very volatile, as the reagent bottle is already giving off a slight whiff of it.

How do I test what the hell this stuff actually is? Are there any chances it was mixed up with something similar?

ninhydric1 - 10-12-2017 at 11:55

Try boiling point and freezing point first. These are usually good for indicating organic compounds in general. Due to the sweet smell, I assume it's an ester, not pyridine.

DraconicAcid - 10-12-2017 at 12:36

Also check to see if it's water-soluble, and measure its density. If it is even slightly water soluble, check the pH of the solution.

And yeah- if it smells sweet, or even tolerable, it ain't pyridine.

ChocolateStirBar - 10-12-2017 at 13:48

It is water soluble and the smell became much more apparent even under strong ventilation upon addition of water, but no "white mist" was observed as has been reported with actual pyridine + water.

I'll check the pH tomorrow and report back.

nezza - 12-12-2017 at 07:25

If it smells remotely pleasant it is not pyridine. Pyridine has a revolting faintly ammoniacal smell and is one of the most unpleasant things I have smelled in the lab.

zed - 12-12-2017 at 17:16

Pyridine smells like strongly rancid butt, in a bad way.

Make yerself a little from Nicotinic Acid. It's special.

https://www.youtube.com/watch?v=FNsqYwzm40M

[Edited on 13-12-2017 by zed]

mysteriusbhoice - 23-12-2017 at 03:53

im gonna guess but maybe it is benzaldehyde or something.
that usually has a sweet smell and is one common solvent used so perhaps they mislabeled it and sold it to you.