ISIAQ STC 11 (Sources, Monitoring and Evaluation: Chemical Pollutants) have hosted webinars to increase communication within the STC11 and expanding our outreach. The upcoming webinar will be on the topic of “New instrumentation/monitoring techniques for faster knowledge.” Below is the webinar information. Please mark your calendar and join us to learn more!
Date: June 19th, 2019 • 9:00-10:00 am. U.S. Eastern Daylight Time
Outlines: One joint presentation (40 minutes) and Discussions (20 minutes)
Presentation: Total OH reactivity measurement using comparative reactivity method (CRM): methodology and application in indoor air study
Abstract: The total OH reactivity is the total loss frequency of hydroxyl radicals (OH) with all compounds present in ambient air. Its inverse is the local lifetime of the OH radical (ca. 100 ms), the most important atmospheric oxidant. Total OH reactivity also represents a measurement of the overall loading of reactive molecules, including those actively participating in chemical reactions leading to ozone and secondary organic aerosol (SOA) formation. Comparison of measured OH reactivity (top-down approach) and OH reactivity calculated from the measured chemical compounds (bottom-up approach) provides a means of chemical budget analysis by giving an estimate of the completeness of measurements. Outdoor reactivity studies have highlighted the presence of unaccounted chemical species (missing OH reactivity, Di Carlo et al., 2004; Noelscher et al., 2016) and speculated what the potential unmeasured compounds could be. Indoor air is influenced by outdoor air ingress, indoor furnishings and human activities, and it is currently not known whether most of reactive species have been identified. In order to answer this question, total OH reactivity measurement is needed in indoor environments. The webinar aims at describing how the OH reactivity is measured through the comparative reactivity method (CRM). The advantages and limitations of the method and some preliminary results of its applications in indoor air measurements from the Sloan funded Indoor Chemical Human Emissions and Reactivity (ICHEAR) campaign will also be discussed.
Dr. Nora Zannoni received her PhD in atmospheric chemistry from University Paris XI with a dissertation on “OH reactivity measurements in the Mediterranean region”. Her PhD thesis focused on the development of an OH reactivity instrument based on the newly developed comparative reactivity method and its deployment in outdoor environments. She is currently employed as postdoctoral researcher at Max Planck Institute for Chemistry in Prof. Dr. Jonathan Williams’s group. Her present research focus includes the investigation of volatile organic compound (VOC) and optical isomers in the Amazonian rainforest and OH reactivity in indoor environments.
Ms. Nijing Wang is currently working in Max Planck Institute for Chemistry as a PhD student funded by MARIE SKLODOWSKA-CURIE ACTIONS ITN Project “IMPACT.” She obtained her masters degree from Hong Kong University of Science and Technology working with chemical composition of atmospheric aerosols. After that, she moved from aerosol phase to gas phase where she now studies VOCs and OH reactivity in both outdoor and indoor environments.