A5051599292- Indoor Air Quality and Microbial Exposure
- Atmospheric Ozone and Climate
- Atmospheric chemistry and aerosols
- Analytical chemistry methods development
- Isotope Analysis in Ecology
- Climate Change and Geoengineering
- Mass Spectrometry Techniques and Applications
- Advanced Chemical Sensor Technologies
- Conservation Techniques and Studies
- Air Quality Monitoring and Forecasting
- Air Quality and Health Impacts
- Toxic Organic Pollutants Impact
- Gas Sensing Nanomaterials and Sensors
- Climate Change, Adaptation, Migration
- Odor and Emission Control Technologies
- Space exploration and regulation
University of Colorado Boulder
2024
NOAA Chemical Sciences Laboratory
2024
Cooperative Institute for Research in Environmental Sciences
2024
National Oceanic and Atmospheric Administration
2024
University of Toronto
2023-2024
Columbia University
2020-2023
The Chemical Assessment of Surfaces and Air (CASA) study aimed to understand how chemicals transform in the indoor environment using perturbations (
Energy-efficient residential building standards require the use of mechanical ventilation systems that replace indoor air with outdoor air. Transient pollution events can be transported indoors via system and other entry pathways impact chemistry. In spring 2022, we observed elevated levels NOx (NO + NO2) originated outdoors, entering National Institute Standards Technology (NIST) Net-Zero Energy Residential Test Facility through system. Using measurements NOx, ozone (O3), volatile organic...
Abstract. Proton-transfer-reaction mass spectrometry (PTR-MS) using hydronium ion (H3O+) ionization is widely used for the measurement of volatile organic compounds (VOCs) both indoors and outdoors. H3O+ ionization, as well associated chemistry in an ion–molecule reactor, known to generate product distributions (PIDs) that include other ions besides proton-transfer product. We present a method, gas-chromatography pre-separation, quantifying PIDs from PTR-MS measurements nearly 100 VOCs...
The chemical composition of indoor air is strongly driven by the and properties surfaces. At Chemical Assessments Surfaces Air (CASA) campaign, we performed controlled additions ammonia (reaching up to 297 ppb 662 ppb) investigate impacts changing surface basicity on fate gaseous particulate acids bases in an unoccupied house. In response injections, nitrogen-containing compounds (C2–7H3–11N1O0–3) were emitted from surfaces gas phase with signals increasing 101% 104% compared their prior...
Gas chromatography paired with proton transfer reaction mass spectrometry allows for a more accurate assessment of gas-phase chemicals in indoor air.
Abstract. Proton-transfer-reaction mass spectrometry (PTR-MS) using hydronium ion (H3O+) ionization is widely used for the measurement of volatile organic compounds (VOCs) both indoors and outdoors. Unlike more energetic methods (e.g., electron impact), H3O+ can leave a target VOC molecule mostly intact thus in PTR-MS spectrum be identified by its mass-to-charge ratio corresponding to proton-transfer product (MH+). However, ionization, associated chemistry reactor, known generate other ions...
Recently proposed as a possible alternative to sulfate particles for stratospheric solar radiation management (SSRM), calcite (CaCO3) aerosols have been modeled minimal negative impact on both ozone level, through heterogeneous chemistry, and temperature. However, the chemistry of CaCO3 with relevant trace gases, such HCl, at conditions is still underexamined. We studied kinetics HCl uptake airborne temperature, 207 ± 3 K, by performing experiments under dry using an aerosol flow tube...
Calcite (CaCO3) aerosols often serve as an idealized proxy for calcium-rich mineral dust. Their use has also previously been proposed stratospheric solar radiation management (SSRM). Little is known about the heterogeneous chemistry of calcite with trace gases HNO3 and HCl therefore their potential impact on ozone (O3). Here we report results experimental study uptake onto submicron CaCO3 particles in two different flow reactors. Products reaction kinetics were observed by impacting...
This study describes laboratory experiments on the reaction HOCl with chloride-containing aerosol and containing selected organic compounds without chloride.
Previous time-integrated (2 h to 4 h) measurements show that total gas-phase water-soluble organic carbon (WSOC