Detection and analytical challenges of Novichok nerve agents: A review from the perspective of the Navalny and Skripal cases

• Review analytical advances in Novichok nerve agent detection workflows • Summarizes physicochemical and toxicological characteristics of Novichok agent • Evaluates GC-MS, LC-HRMS, NMR, and biosensing methods for identification • Discusses field-deployable detection and verification procedures and advances Novichok agents, a class of highly toxic organophosphorus nerve agents developed in the late 20 th century, appeared as a public perceived threat in the context of Chemical Weapons Convention alleged non-compliance. Their extreme toxicity, environmental behaviour, and structural diversity present several analytical challenges across environmental, biomedical, and forensic contexts. Following high-profile incidents, the international scientific community has intensified efforts to detect, identify, and monitor Novichok agents at trace levels. However, obstacles such as the lack of standardized reference materials, representative compounds selection, the need for sensitive, selective, and field-deployable detection platforms pose challenges for the analytical workflows. This review aims to provide a comprehensive look on the physicochemical properties of Novichok compounds, their transformation pathways, and the latest advances in analytical methodologies for their detection and identification. Emphasis is on analytical techniques such as gas and liquid chromatography coupled with high-resolution mass spectrometry (GC-MS, LC-HRMS), nuclear magnetic resonance (NMR), immunochemical assays, and sensor technologies, as well as on field deployable solutions such as ion mobility spectrometry (IMS), Fourier transform infrared spectroscopy (FTIR), Raman, etc. Additionally, sampling protocols, derivatization strategies, and data interpretation models are discussed. Critically discussed are the challenges associated with real-time detection, on-site field analysis, and confirmation under the protocols of the Organization for the Prohibition of Chemical Weapons (OPCW). This review attempts to provide guidance for analytical chemists and CBRN responders in refining detection workflows and enhancing preparedness against emerging chemical threats like Novichoks.