Paper from 1st of January 2017 where Iranian researchers synthesized Novichok agents.

Iranian chemists identify Russian chemical warfare agents - Ezine - spectroscopyNOW.com

Chemical weapons’ detection requires good analytical data


Chemical weapons, and their precursors, were banned by the Chemical Weapons Convention, which has been signed and ratified by nearly all the countries in the world. However, the illegal use of chemical weapons, whether by state agencies or terrorist organisations, remains a threat. Chemical weapons were used by Iraqi forces in the 1980s against Iranian forces and Kurdish civilians. Some chemical weapons, such as chlorine gas, are believed to have been used in recent years in the Syrian civil war.

Current databases include mass spectra of the more common chemical warfare agents; however, more work needs to be carried out on rarer agents. The so-called ‘Novichok’ agents are a range of highly toxic nerve agents developed in the Soviet Union in the 1970s and 1980s. The literature on their spectral properties is sparse.

The detection of chemical weapons may involve samples in which they are present at extremely low levels. Mass spectrometry is generally used for identification, typically GC/MS or LC/MS. Even with these techniques, identification may be difficult in situations where the molecular ion is weak or isomeric compounds could be present. It is important to recognise typical fragmentation pathways in order to reliably identify the compounds.

GC/MS and LC-MS/MS used for ‘Novichok’ agent detection

The Iranian researchers synthesised five ‘Novichok’ agents, along with four deuterated analogues. They were all O-alkyl N-[bis(dimethylamino)methylidene]-P-methylphosphonamidate compounds (i.e. molecules with the typical nerve agent phosphorus group coupled to N,N,N’N’-tetramethylguanidine). The O-alkyl group was varied, with the methoxy, ethoxy, isopropoxy, phenoxy, and 2,6-dimethylphenoxy derivatives being prepared. The syntheses were carried out on a micro-scale in order to minimize exposure.