Revealing the origin of chemical weapons

Toxic chemicals have been used as a weapon since ancient times. In case of an alleged use of chemical weapons, forensic investigations are conducted to investigate whether a chemical attack has happened and if so, to establish the nature of the utilized agent. In addition to chemical identification, it is important to determine the origin of chemical threat agents, to accurately reconstruct events and identify the perpetrators or exonerate innocent suspects. Forensic intelligence is of key importance to obtain crucial information to accelerate solving a crime, with the ultimate goal to prevent criminal acts before they are executed. This thesis contributes to that goal by presenting multi-analytical profiling strategies for chemical weapons to support forensic intelligence purposes. The potential of chemical attribution of fentanyl and several analogues in biomedical samples was demonstrated. In addition, site-specific chlorinated protein adducts were identified by high-resolution mass spectrometry as a more selective indicator of chlorine gas exposure. Even three months after exposure, nerve agent biomarkers were detected in dried blood spots with a portable detector and laboratory analysis. Subsequently, a novel approach was introduced for analyzing protein adducts in vegetation as evidence of the release of chemical warfare agents. Specific biomarkers for sarin, sulfur mustard, a Novichok nerve agent, and chlorine gas, were detected months after exposure. Lastly, the development of novel matrix-matched standards and statistical methods facilitated elemental profiling of polymer evidence. Overall, this thesis provides chemical profiling strategies for multiple chemical warfare agents and various pieces of evidence to support forensic investigations.