Atmospheric Chemistry Program Seminar: Jennifer Berry, NIST

Vapors and Aerosols: NIST’s forensic approach to arson and cannabis intoxication
Jennifer Berry,
National Institute of Standards and Technology
"The National Institute of Standards and Technology (NIST) is world-renowned for making standards and precise measurements with advanced measurement techniques. The Fluid Characterization Group, part of the Boulder-based Materials Measurement Laboratory, is rooted in precise thermodynamic measurements of fuels and has successfully developed technologies and methods for forensic vapor and aerosol detection. The group’s Dynamic Vapor Microextraction (DVME) was originally developed for vapor pressure measurements of low volatility, unstable molecules but has been expanded towards a variety of forensic applications, particularly for the detection of arson from fire debris. The instrumental development for this new application needs to be thoroughly planned and designed to encompass a large number of factors and their interactions, breaking from a one-factor-at-a-time method. Conducting a sensitivity analysis permits the exploration of multiple variables at the same time while limiting the number of experiments needed. When coupling a sensitivity analysis with DVME in a fire debris study, we found that both the metric and the experimental plan played a crucial role in determining the importance of different instrumental and sample factors. Beyond fire debris, the group has also been developing and testing breath collection techniques to detect cannabinoids in breath after cannabis use. Aerosols and condensed vapors will be collected with two different devices to investigate changes in breath compounds and concentrations after cannabis use. While cannabinoids have been detected in breath aerosols, additional explorations into exhaled breath condensate as a part of a 128- participant study will use a cannabinoid targeted and metabolomics untargeted approach to explore if this type of noninvasive breath collection is a valid method as well. With the growth of forensic research in NIST Boulder, numerous opportunities are available for collaborations, internships, and postdoctoral fellowships at NIST Boulder."