Saturday, March 4, 2017

The chemical reaction that probably killed Kim Jong Nam

(Cross-posted from Medium here)

On February 13, a 45-year old man by the name of Kim Jong Nam was making his way through a Malaysian airport to catch his flight home to Macau. Without warning, two women approached him in succession and smeared an oily substance over his face. Within 20 minutes, the man was dead. The two women are alive, and in custody.

As you probably know by now, Kim Jong Nam was the half-brother of North Korean dictator Kim Jong Un. Being the eldest son of their father Kim Jong Il, he was the prince that could have been but never was, and instead lived a lonely and reasonably paranoid life of exile mostly outside of North Korea.

Motives and details regarding his assassination are murky, but it is reported that he was killed by a nerve agent called VX. This toxin is deadly in ridiculously small amounts, and classified by the United Nations as a weapon of mass destruction.

In terms of diabolical assassination schemes successfully executed, this incident is on par with the death of Bulgarian dissident Georgi Markov by ricin delivered via umbrella, or the death of Russian dissident Alexander Litvinenko by radioactive polonium-210.

Among the questions raised by the Kim Jong Nam investigation currently underway, there are two that seem connected:

1. Why were two persons used to carry out this murder?
2. Why were neither of the two persons severely harmed or killed by the VX toxin they administered?

The most probable answer* to both questions is that the VX nerve agent was administered in a binary fashion. In other words, the two women each delivered a different chemical substance, and those two substances reacted on the spot (i.e., on the man’s face) to produce the VX toxin. Since both substances would be relatively harmless on their own, neither of the two women suffered Kim Jong Nam’s fate.

The hypothetical mode of VX poisoning that Nam suffered, via delivery of the precursor compound QL by one assailant, and the delivery of sulfur by the other assailant.

The first compound in this scenario would be an oily, colorless liquid called QL, or technically, N-[2-[ethoxy(methyl)phosphanyl]oxyethyl]-N-propan-2-ylpropan-2-amine. As you might guess from that name and can see from the diagram, it is a bit complex and would require some serious Walter White-like chemistry skillz to produce in a lab. It is a low-toxicity precursor to VX, only lacking a sulfur to make it deadly.

The second compound would be some form of sulfur, which is safe and easy to obtain. Sulfur reacts instantly with QL to form the VX nerve agent, or N-[2-[ethoxy(methyl)phosphoryl]sulfanylethyl]-N-propan-2-ylpropan-2-amine if you want to get technical.

In this scenario, the first assailant would be safe from any incidental exposure to VX, but not the second. And indeed, it was reported that one of the women had to vomit following the incident.
The binary form of chemical weapon delivery is not uncommon. Countries that have stockpiled large volumes of chemical weapons like VX usually store the precursors rather than the actual agent whenever possible. Obviously, it is much safer approach.

VX is has its origins in insecticide research, and is molecularly similar to what you would find in common yard pesticides containing malathion or other organophosphates. It is literally a human pesticide that goes straight to the nervous system and locks muscles into their contracted state, eventually asphyxiating the victim. It is death by torture.

Although the U.S. claims to have eliminated its massive stockpiles of VX manufactured during the 1960s, it is believed to be on hand in other countries including Russia, and possibly Syria and North Korea. Hopefully, if nothing else, this incident can arouse awareness of the potential terror of mass chemical warfare, and urge us toward global action in eliminating its influence on the planet we share.

*There are, of course, other possible explanations. See here, for instance.