Novichok, a lethal nerve agent, emerged on 4 March 2018 after Russian spy and British double agent Sergei Skripal and his daughter, Yulia, were poisoned in Salisbury. This ominous toxin, however, is not a recent development; it has been lingering under the radar since its origins in 1970s Soviet Russia, where it was passed between labs in Soviet Uzbekistan and Kazakhstan for refinement and testing. It was created to be deadlier than its predecessors and marks the beginning of a fourth generation of chemical weapons, with its main objectives being: undetectable, able to bypass 1970s NATO chemical gear, and to circumvent banned chemicals in the Chemical Weapons Convention.
What is understood about the structure of Novichok is widely from testimonies of Russian scientists. It is believed to consist of an organophosphate backbone with alkyl branch groups (carbon chains) containing mixtures of fluorine, nitrogen and oxygen bonded atoms. It is extremely potent, five to ten times more so than previous nerve agents, making it fatal to humans even in tiny amounts. The chemical can enter the body via ingestion, skin contact, or inhalation, making it extremely difficult to avoid and easy to deliver. The main way Novichok attacks the body is by reacting with an enzyme named AChE which helps the body with neurotransmissions. When this enzyme is denatured, it can no longer help with the breakdown of neurochemicals in the body. These accumulate throughout the nervous system causing overstimulation of nerve junctions, leading to involuntary muscle contractions and loss of communication with key organs. Over time, breathing becomes harder and eventually, if not treated, causes respiratory failure and cardiac arrest.
In 2018, Novichok was infamously used in Salisbury on Sergei and Yulia Skripal in an attempted assassination by Russia, although their involvement has been denied. Both were found on a bench in critical condition seizing with wide open eyes and “slipping in and out of consciousness”. They were rushed to hospital and underwent months of critical care. It was discovered that the agent had been administered by contact with a perfume bottle within the Skripal’s house that contained enough to kill thousands of people. In order to combat the agent within their bodies, decontamination was paramount to prevent further damage to nerves. This is then followed by a chemical named Atropine, which works to competitively bind to receptors at nerve junctions, namely cholinergic receptors, which then prevents the binding of the accumulated chemicals and subsequent overstimulation, essentially acting as a blocker to the receptors. However, it is not an antidote and may not fully reverse the effects of the poison, and so further medical interventions such as oximes and serious care will help the patient to recover.
Due to the animosity surrounding Novichok, chemists do not have on-site biosensors, able to immediately identify the presence of the compound. Therefore, chemists have had to employ a variation of techniques for detecting Novichok agents within the body. One of these methods takes samples of bodily fluids, such as urine and blood, and subjects them to different analytical techniques known as Mass Spectrometry and Liquid Chromatography in order to identify degradation products of Novichok. Mass Spectrometry deals with the mass to charge ratio of ions in order to determine molecular composition, whereas liquid chromatography separates the liquid mixtures into their individual components for further analysis. By comparing spectra and expected values, chemists can determine, to a high degree of certainty, the presence of novichok agents. Samples from other sources can be taken before undergoing similar analytical techniques; however, they mainly come from external places including environmental traces of Novichok from around the suspected area. For example - in soil, air and surfaces.
Aside from the difficulty in knowing when Novichok is being produced in facilities around the world, it is also extremely difficult to identify once it has been produced as it is a binary poison. This means that it requires two stable chemicals that when mixed form an active poison. This allows it to be manufactured ‘legally’, as its components do not violate convention laws, but also makes it very easy to transport unflagged and so can bypass security very easily.
Further research needs to be conducted into active Novichok by looking at potential components that could result in their formation. This will give modern toxicologists the tools to create specialised equipment designed to identify Novichok on site using biosensors containing engineered enzymes, but also the knowledge to identify and flag any potentially suspicious compounds that could be used for these purposes.
Novichok’s chemistry embodies a chilling reality of modern warfare. Developed clandestinely and designed for lethal effectiveness, its detection poses an ongoing challenge to chemists. Through the efforts of scientific research, methods of identification have evolved, but antidotes and rapid response poison mitigation are still in serious development.
Novichok serves as a stark reminder of the enduring consequences of chemical weapons proliferation and proves that there are some things we cannot prepare for. What might be the next weapon that science has to catch up to?
