31–40 of 84 posts
Earlier quoted context omitted.
Dimethylmercury is (or was, at least historically) used as a reference material for nuclear magnetic resonance (a common analytical method used in chemistry): https://sites.northwestern.edu/ohalloran/199hg-nmr-standards... This MIT incident was in a chemistry building that has been in use since 1970, so it could have been accidental release of an old, unused container or sample tube of the material.
Thanks! 40+ years ago I worked in a marine biology lab as a dishpig for seawater analysis and we had fun times when the annual clear out found a gallon jug of benzene at the point of panic about benzene being replaced by toluene.
Put that in perspective against industrial quantities where a hardhat operator opens the hatch on a very full compartment of a chemical tanker, looking at their mirror image reflecting up from the surface of a few hundred tonnes of cargo a few feet below.
Which is then carefully sampled and delivered to a lab where they check for trace water in the benzene.
Other "sources" (using the word loosely as their provenance is unclear) > "based on the information available, this was a localized issue with only one student directly exposed. Their reported use of dimethyl mercury was unauthorized. MIT does not allow the purchase or synthesis of dimethyl mercury." [1] Karen Wetterhahn's exposure and death [3] is a cautionary tale of the extreme toxicity of dimethyl mercury, and wa…
Holy hell. I would've have believed it was possible for a non-biological substance to be so toxic.
Other "sources" (using the word loosely as their provenance is unclear) > "based on the information available, this was a localized issue with only one student directly exposed. Their reported use of dimethyl mercury was unauthorized. MIT does not allow the purchase or synthesis of dimethyl mercury." [1] Karen Wetterhahn's exposure and death [3] is a cautionary tale of the extreme toxicity of dimethyl mercury, and wa…
> Less than 0.1 mL is capable of inducing severe mercury poisoning resulting in death Holy hell. I would've have believed it was possible for a non-biological substance to be so toxic.
From https://en.wikipedia.org/wiki/Cyanide_poisoning
> A fatal dose for humans is on average 1.52 mg/kg of body weight
Assuming 80kg(175pounds), that's like 120mg of Cyanide.
There is probably even more nasty stuff.
Derek Lowe mentions dimethyl mercury as the first substance that's not worth the risk: https://www.chemistryworld.com/opinion/a-risk-not-worth-taki...
His "Things I Won't Work With" series on Science ( https://www.science.org/topic/blog-category/things-i-wont-wo... ) is fun to read. The link in the article itself now unfortunately just points to the science.org homepage so you have to do some clicking around to get to this blog series.
(Well, the poor woman, then, this article ...)
Some guy's in the hospital from handling droplets of instant liquid death and they're worried about feelings being hurt?
https://www.science.org/content/blog-post/alleged-dimethylme... ("The Alleged Dimethylmercury Incident")
Seems the initial reporting may have been misleading. There was apparently *no* dimethylmercury exposure, after all: and MIT doubts it was synthesized in the first place.
To detect elemental mercury vapor, the air is drawn in to a controlled chamber where if present it amalgamates with pure gold as the reference (zero) material, and determined electronically.
I don't think this works with organic mercury like dimethylmercury. It is an organo-metallic compound and behaves very unlike elemental mercury.
I'd be running the AA's from the analytical labs in mercury-vapor mode, putting them on carts if necessary since they do not need gas supplies for mercury detection & measurement.
Before plasma-emission spectrometers became widespread, more people were familiar with the traditional atomic-absorption (AA) instruments.
Instead of measuring the combined emission of any elements present in the sample, the AA used the steady emission of the target element alone as reference, from a (expensive) lamp having that specific element present within its hollow cathode.
AA normally uses a clean acetylene flame to vaporize the sample, with the reference light beam passing above the flame. If the target element is present in the sample, it absorbs some of the characteristic wavelength from the beam and is detected as a negative deviation from baseline.
For trace mercury though, the flame was not good enough, so an even more expensive and complex graphite furnace was installed in place of the burner.
Either way the light beam passes through a few inches of lab air to get from the lamp to the optical detector.
And you don't need the burner or the furnace to detect things that are already vaporized.
The graphite furnace would be good to calibrate with later if you couldn't do it in advance.
I wonder if their contractor has as good detection ability as MIT itself.
Can someone who knows a thing or two about chemistry explain why one would need to synthesize or purchase this chemical. Given that it involves a student I'll take "because of bragging rights to impress everyone" as a valid response, but wondering if it has any value is otherwise? Is it one of those "well despite its danger it's still the best at X, Y and Z and nothing else comes even close"?
Edit: reading further down the comments, Derek Lowe is guy.