Melgar
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Mercury thermometer broke, and fell into methyl iodide boiling flask. How concerned should I be?
I feel like this can't be good, considering the toxicity of methyl mercury species, but I'm not sure what the correct protocol is here. There
wouldn't have been much methyl iodide in the flask, although there was a lot of iodine and methanol. Any advice?
[Edited on 8/10/17 by Melgar]
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Sulaiman
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Coincidentally, 27 July I put 2.56g (slightly more than stoichiometric as I intend to heat it later) iodine prills on 3.93g liquid mercury,
the surface tension of mercury initially kept the reagents pretty much apart, but,
at rt, with shaking, within seconds the mercury became immobile,
giving a red/brown solid mass at the bottom with coating on the remaining prills and test tube wall,
and a small quantity of greenish compound at the very bottom (like almost anhydrous CuSO4), that mostly changed to black over a few days.
So I'm sure that HgxIy forms quickly,
as for the other interactions I'm sure that you know much more than me..
I guess that excess sodium carbonate will react with most of the species to eventually form basic mercuric carbonates plus others ?
http://www.sciencemadness.org/talk/viewthread.php?tid=10019
[Edited on 10-8-2017 by Sulaiman]
CAUTION : Hobby Chemist, not Professional or even Amateur
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clearly_not_atara
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I think you made this:
https://pubchem.ncbi.nlm.nih.gov/compound/iodo_methyl_mercur...
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Cryolite.
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http://orgsyn.org/demo.aspx?prep=cv2p0399
Note 13: Caution. Methyl iodide in contact with mercury when exposed to the sunlight readily forms methylmercuric iodide, which is exceedingly
poisonous.
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JJay
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What is the best way to neutralize something like that? Concentrated sodium thiosulfate?
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CRUSTY
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Like Cryolite more or less said, if you have formed methylmercuric iodide, you've got an issue on your hands. It falls under the same PEL ranges as
dimethylmercury, and is also, like it's dimethylated cousin, absorbed through skin contact. So it's a huge issue if you made
methylmercuric iodide.
Unfortunately, there is very little research at all on MMI, so unless you're hell-bent on keeping that methyl iodide, I'd suggest finding a hazardous
waste disposal service or method (my local dump has "hazardous waste days").
I did, however find something that I think could be used if you are up for a little experimentation in this RSC article
I think there could be some merit to exposing the mixture to intense UV light in the presence of benzene to yield short-chain saturated alkanes, as
well as toluene or a further-methylated benzene derivative. The only issue is that you will lose some of your methyl iodide in the process, since
methyl iodide also undergoes UV photolysis, although the iodine radical formed might help by bonding to the mercury iodide radical potentially (I am
not sure what the exact radical produced is) formed in the MMI photolysis, yielding mercury (II) iodide.
I'm merely speculating. I wouldn't try any of this without considering every single possible side reaction. Honestly though, your best bet is to
dispose of it as hazardous waste, because MMI is incredibly toxic.
[Edited on 11-8-2017 by CRUSTY]
[Edited on 11-8-2017 by CRUSTY]
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Melgar
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What if I just carefully add the whole lot of it into a concentrated potassium hydroxide solution? Presumably there might be methylmercury in
solution, although I do have a bottle of mercury test strips for testing drinking water, which I bought some time ago in case a situation like this
came up. My suspicion is that I have mostly mercury II iodide, and metallic mercury, which I already removed using a pipette. Potassium hydroxide
would presumably precipitate HgO as a yellow, insoluble solid.
Ascorbic acid could also work, since it would reduce both mercury and iodine, but that would result in an acidic solution which is less good.
Potassium ascorbate, perhaps?
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CRUSTY
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KOH should be alright. There is very little documentation on methylmercuric iodide, but methylmercuric chloride is a solid at STP, so the iodide
counterpart may be a solid as well, in which case it would filter off with the HgO.
Just be incredibly careful. Alkyl mercury compounds are extremely neurotoxic and will penetrate many plastics, as well as your skin. It also has vapor
pressure of around 50 mmHg, so it is pretty volatile. I live within half an hour of Dartmouth, and so I often hear the story of the professor that
worked there (I can't remember her name at the moment) who got a single drop of dimethylmercury on her thick latex glove, took the glove off, and died
a year later of mercury poisoning. The PEL for alkyl mercury compounds is 0.01 ppm. Sure, maybe no methylmercuric iodide was produced, but you can
never be too careful with these things.
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