Thallium

[Richy]

Today in forensic science class, we watched and interesting program about a murderer who poisoned a whole family's coca cola delivery with the metal thallium. he chose the poison because it would be difficult to detect with blood testing, and there was no known cure! what is interesting, however, is that as soon as natural Tl is added to the carbonated water in the coke, it fizzes over the brim and spills everywhere. The Tl also leaves a precipitate in the bottom of the bottle. Now I figured that the precipitate could be removed by heating the coke at first, thus increasing the solubility so there wouldn't be any crap at the bottom, but how do you think the murderer would have created a Tl rich chemical that wouldn't overflow the bottle?

[EP]

Just some info for historical interest: Thallium was used to poison large ammounts of canned food (mostly meat I think) in Rhodesia (now Zimbabwe) that was then distributed by the white minority government to black villagers, killing and sickening hundreds. Anthrax and other biological weapons were also used against civilians by the goverment in this war, assisted by the white minority South African government.

[nbk2000]

Maybe the thallium formed an insoluble carbonate or phospate with the coke? Heating the soda would make it flat, and thus undrinkable, defeating the whole purpose.

You may also be aware of a little rule we have around here called the "NO NEWBIES POSTING NEW TOPICS!" rule. You seemed to have missed that one, eh?

Your post may stay, but since you not only broke this rule, but put this topic in the wrong section to boot, you may not.

Bye bye. :)

[Bitter]

Thalium is a trace element in the body, I believe, but high levels of it must be fatal (like salt).

[Boob Raider]

Hey Richy I have also seen that episode but like 4 years ago. That dude(Killer) had shitty high IQ and he was a member of MENSA. Anyways that compound of Tl was an old compound from some cook book (as mentioned in the episode) and not his own invention. He also used elemental Tl to start with and I do remember the use of H2O2 in the preperation. I strongly suspect that it was an organic compound as like mentioned ionic salts will ppt. as CO3 or/and PO4. Like TEL (Tetra Ethyl Lead) a Highly toxic Pb compound was used to increase octane # of gas but it is not soluble in H2O but in HC's (made by - Heating Na/Pb,4:1, alloy with liquid Ethyl Chloride under pressure). So I guess something H2O soluble with Tl can also be made.

[vulture]

Tl2CO3 is soluble in water and this would have been the most likely thallium compound present (next to TlHCO3) because of the H2CO3 in the coke.
Thallium compounds color a bunsen flame intensely green.

I wonder how the dude got the thallium because it most be a rather expensive compound with some serious restrictions on it.

<small>[ August 28, 2002, 12:46 PM: Message edited by: vulture ]</small>

[megalomania]

I saw that episode on the Discovery channel. He was some sort of chemist so he bought the stuff. This was eventually discovered after a search of his shed/lab. I remember the snide little comment by the police that he was so smart he didn't bother to get rid of the rest of the chemical. That chemical excess proved quite damning to him.

When adding solid chemicals to liquids where speed is of the essence (like adding something to a bitches drink) it is best to dissolve such substances beforehand. No powder floating around, no residue on the bottom. One could add this to a bit of heated Coke, and then add that to the whole.

[spydamonkee]

yea it is interesting how simple some of the most complex plans are broken by investigating authorites after they find a stupid mistake that the perp overlooks
bragging after you think u have gotten away with it is one of the most common i think

[nbk2000]

Using heavy metals like thalium, lead, arsenic, or mercury to poison someone is rather stupid. These are elements and, as such, are not going to degrade or disappear.

They (the pigs) can detect heavy metal poisoning in 5,000 year old mummies, so good luck getting away with it.

What's needed is highly volatile and unstable organic molecules that will decompose into common molecules within a very short period of time, thus evading detection.

Azides turn into amines, which are common in corpses. Succinylcholine Chloride into succinyl chloride and choline, common chemicals in the body. These are difficult to detect in bodies if not specifically looking for them.

Oh, and thallium has interesting symptoms like bleeding from the skin, teeth falling out, hair too. These are NOT typical disease symptoms...unless you live in Chernobyl. :D

Many a would-be poisoner has warned the victim with the "powdery substance floating on the rink" mistake. And the roofie rapists make the mistake of dumping the powdered pill into the drink and wonder why the bitch doesn't drink the drink with the blue sludge at the bottom. :rolleyes:

Pre-dissolve your shit in distilled water, load it up in a cut-down diabetic syringe, and you can squirt it into a drink from across a table (with practice) with no one who may be watching any the wiser since the stream is invisible from more than a foot or two away.

With HCN or other volatile inhalant poison, you could spritz someone right below their face (on their shirt) and the rising vapors will knock them out. Or spritz their back just before they get into a car and the vapor concentrations will rise till they die, delaying the onset of death from the actual application, confusing the police as to when they were poisoned.

The RTPB was indeed to educate people in how to avoid making coomon mistakes that trip up most first time criminals. The MENSA guy could have done with reading it since his genius obviously didn't extend to matters of crime.

<small>[ August 29, 2002, 09:34 AM: Message edited by: nbk2000 ]</small>

[vulture]

You're only a real genius if you know how to put your genius to good practice...

[Rhadon]

By chance I found out that prussian blue can be used as an antidote for thallium.

Prussian blue fixes the thallium in its crystal lattice, thus making it unresorbable. It is applied orally, at best before the resorption has taken place. If it has taken place, though, 3 - 20 g of prussian blue are administrated in small doses spread over the day.

source: the German pharmaceuticals list "Rote Liste"

[nbk2000]

Chelation with EDTA is the usual treatment for heavy metal poisoning in the US.

[vulture]

Chelation reminds me of Srontium 90, a radioactive isotope of strontium which builds up in the body in bones, because it is very similar to calcium. The nasty thing is that it can't be removed by chelation and the body is being radiated from inside.

[Rhadon]

In Germany EDTA is only used as an antidote against Pb, Co, Cu, Mn, Cd and transuranium elements. I doubt that it is applicable for poisonings with other heavy metals.

[malzraa]

Hey I saw that one too:) I think it was either "Exhibit A" or "Medical Detectives". I also saw a one about a wife you slowly added thallium from old rat poison into her husband's coffee. The thallium is never purged from the human body, so it just built up until his hair fell out and he went into a coma. The thing that caught her though was the fact that he was renovating an old lab with thallium in it, and they eventually did a test on his hair, creating a timeline of all his thallium doses. That is kind of an undesirable effect, as it collects in all parts of the body.

[vulture]

A very old, but still used and very reliable test for arsenic poisoning is the marsh test.

A small probe is reacted with Zn+HCl (both arsenicfree!) to form AsH3. This is then passed through a heated glass tube and the AsH3 decomposes into As, which settles down as a thin layer on the walls, and hydrogen which is burnt.

If the layer dissolves in NaOCl, it's arsenic. This test is pretty specific (maybe antimony would give the same results?) and can detect very small traces of arsenic as the layer is already visible in the ppm range.

[Arthis]

You can buy some pure thallium here (http://www.tinfosnizi.com/products/products_non_ferrous_metals.html) . I doubt you need any authorization since it used to be OTC. May have changed though.
It seems that thallium in rat poison is still common in some countries. If one wants to travel...

btw, what is cyanide poisoning you could recognize with a garlic odor on the cadaver ?

[EDIT]: cyanide not cyanure, stupid froggy ! ;)

[yt2095]

Cyanide smells like almonds. Phosphines smell like garlic :)