Forensic Science Breakthrough Makes Detecting Chemical Weapon Evidence Easier Than Ever
Molecules left over in the ground, water, or on an object after a chemical attack have the potential to aid law enforcement officials in determining what happened at a chemical attack site long after it has occurred. Therefore, advances in Forensic Science are important in helping law enforcement officials determine if chemical weapons were utilized. Recently, researchers at Lawrence Livermore National Laboratory (LLNL) have developed a new and very sensitive technique for detecting the presence of the nerve agent Soman, which will allow them to provide more scientific evidence to support international law enforcement investigations.
The Lawrence Livermore National Laboratory is one of the world’s leading laboratories for chemical analysis and forensic science. The Forensic Science Center (FSC) at LLNL is one of only two laboratories in the United States that can receive and analyze chemical samples that were collected by the Organisation for the Prohibition of Chemical Weapons (OPCW) and submitted for analysis. In order to keep this certification, the Forensic Science Center (FSC) at LLNL must complete its annual proficiency test that is administered by the OPCW.
The Lawrence Livermore National Laboratory (LLNL) team developed an analytical
methodology capable of identifying pinacolyl alcohol (PA), a unique forensic marker generated both during the synthesis of the nerve agent Soman and through its environmental degradation. The breakthrough relies on the first reported chemical derivatization of pinacolyl alcohol using 1,1′-carbonyldiimidazole (CDI) to produce pinacolyl imidazolyl carbamate (PIC), a derivative that significantly improves analytical detection. The findings, published in ACS Omega, received the journal’s Editor’s Choice Award and were featured on the journal cover.Pinacolyl alcohol is a critical forensic marker because it is both a product of Soman synthesis as well as a byproduct of the degradation of Soman in the environment. The detection of pinacolyl alcohol in the environment supports the former use of the nerve agent, as pinacolyl alcohol generally is a synthetic chemical rather than a naturally occurring chemical.
Detecting Soman is difficult for many reasons.
Chemical agents rarely remain intact once released into the environment. Factors such as temperature, humidity, sunlight, and pH rapidly degrade Soman into trace amounts of detectable chemical markers. Forensic laboratories must therefore identify these minute quantities amidst complex environmental matrices containing numerous naturally occurring organic and inorganic compounds. To demonstrate the method’s practical applicability, the LLNL team optimized and validated the analytical workflow using Virginia Type A soil and silt sediment, closely simulating real-world environmental samples encountered during chemical weapons investigations.
In addition, forensic scientists must contend with additional analytical challenges when using traditional methods to identify pinacolyl alcohol. The relatively low molecular weight of pinacolyl alcohol (C₆H₁₄O; MW = 102.17 g/mol) makes its identification by gas chromatography-mass spectrometry (GC-MS) particularly challenging in trace environmental samples. Its low molecular mass produces limited high-mass fragment ions during electron ionization, reducing analytical specificity in complex matrices. While liquid chromatography mass spectrometry (LC-MS) is an ideal analytical methodology for identifying compounds at low concentrations, pinacolyl alcohol has limited ionization properties and therefore is not an ideal compound for determination by LC-MS.
New Analytical Innovation Through Chemical Derivatization
To overcome these analytical limitations, researchers at Lawrence Livermore National Laboratory (LLNL) developed a chemical derivatization strategy in which pinacolyl alcohol undergoes carbamoylation using 1,1′-carbonyldiimidazole (CDI) to form pinacolyl imidazolyl carbamate (PIC). The addition of the imidazole-containing carbamate group improves chromatographic behavior for GC-MS while simultaneously introducing robust protonation sites that enable highly sensitive detection by LC-HRMS. This enables independent confirmation of the same forensic marker using two complementary analytical techniques. As Carlos Valdez, LLNL Associate Program Leader for Research and Development at the Forensic Science Center (FSC), explains, “Verification through two independent or orthogonal analytical methods significantly enhances the validity and strength of OPCW-submitted official data.”
This dual-verification capability represents an important advancement in chemical weapons forensic science by enabling more reliable identification of Soman-related forensic markers from complex environmental samples. The ability to independently confirm results using both GC-MS and LC-HRMS significantly strengthens the evidentiary value of analytical findings submitted for OPCW investigations.
Building on this success, the researchers plan to extend the CDI derivatization strategy to additional alcohol-based forensic markers associated with other categories of chemical warfare agents. Although the research is still evolving, this methodology has already expanded the analytical capabilities available to international forensic investigators and treaty verification organizations. By enabling sensitive, orthogonal confirmation of Soman-related markers from environmentally degraded samples, the work strengthens the OPCW’s mission to verify compliance with the Chemical Weapons Convention and highlights the critical role of advanced analytical chemistry in generating reliable forensic evidence when traditional forms of documentation are no longer available.
