About | HeinOnline Law Journal Library | HeinOnline Law Journal Library | HeinOnline
LOG IN
LOG IN

GAO-21-271SP 1 (2020-12-21)

handle is hein.gao/gaobaecen0001 and id is 1 raw text is: Science, Technology Assessment, and Analytics SCIENCE & TECH SPOTLIGHT: TRACING THE SOURCE OF CHEMICAL WEAPONS /// THE TECHNOLOGY What is it? According to the Global Public Policy Institute, there have been more than 330 chemical weapons attacks since 2012. Such attacks are prohibited under the Chemical Weapons Convention. A set of methods called forensic chemical attribution has the potential to trace the chemical agent used in such attacks to a source. For example, investigators could use these methods to identify the geographic sources of raw materials used to make the agent, or to identify the manufacturing process. Such information can aid leaders in deciding on whether or how to respond to a chemical weapons attack. Sample collection Analysis and Source attribution and preparation identification Sources (left to right): kaninstudio/stock.adobe.com; Sodel Vladyslav/stock.adobe.com; GAO illustration. I GAO-21-271SP How does it work? Forensic chemical attribution is a three-step process, though the third step is being developed (see Fig. 1). First, a sample is taken from a victim or the site of an attack. Second, the sample's chemical components are analyzed and identified (see Fig. 2) either at a mobile lab or at one of 18 authorized biomedical labs worldwide. Common identification methods are: * Gas chromatography, which separates chemical components of a mixture and quantifies the amount of each chemical. * Mass spectrometry, which measures the mass-to-charge ratio of ions (i.e., charged particles) by converting molecules to ions and separating the ions based on their molecular weight. * Nuclear magnetic resonance (NMR), which can determine the structure of a molecule by measuring the interaction between atomic nuclei placed in a magnetic field and exposed to radio waves. NMR is the same principle as magnetic resonance imaging (MRI), used in medical diagnostics. In the third step-still under development-investigators use the data from the forensic chemical identification and analysis methods from step two to develop a chemical fingerprint. The fingerprint can be matched to a database of information on existing methods or known source to identify chemical agents (i.e., Source A matching Sample 1 of Fig. 2). However, a comprehensive database containing complete, reliable data for known agents does not exist. How mature is it? Forensic chemical analysis and identification (i.e., Step 2 of Fig. 1) is mature for known chemical agents. For example, investigators determined the nerve agent sarin was used in an attack on civilians in 2017. The methods can also identify new agents, as when investigators determined the chemical composition of the Novichok nerve agent after its first known use in 2018. Forensic chemical analysis and identification methods are also mature enough to generate data that investigators could use as a chemical fingerprint' - that is, a unique chemical signature that could be used in part to attribute a chemical weapon to a person or entity. For example, combining gas chromatography and mass spectrometry can provide reliable information about the chemical components and molecular weight of an agent. To achieve Step 3, scientists could use these methods in a laboratory experiment to match impurities in chemical feedstocks of the weapon to potentially determine who made it. In an investigation, such impurities could indicate the geographic origin of the starting material and the process used to create the agent. Sample identification and analysis Sample 1 I Sample 1 I --- - ~ a- I - - Source A Source B Source C Source: GAO. I GAO-21-271SP GAO-21-271SP Tracing the Source of Chemical Weapons

What Is HeinOnline?

HeinOnline is a subscription-based resource containing thousands of academic and legal journals from inception; complete coverage of government documents such as U.S. Statutes at Large, U.S. Code, Federal Register, Code of Federal Regulations, U.S. Reports, and much more. Documents are image-based, fully searchable PDFs with the authority of print combined with the accessibility of a user-friendly and powerful database. For more information, request a quote or trial for your organization below.



Contact us for annual subscription options:

Contact Us

Already a HeinOnline Subscriber?

Log In

profiles profiles most