AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Development of an Innovative Aerosol Generation Setup for In-vivo Exposure Studies
SINA TAGHVAEE, Amirhosein Mousavi, Mohammad Sowlat, Constantinos Sioutas, University of Southern California
Abstract Number: 22 Working Group: Instrumentation and Methods
Abstract In this study, we developed a new setup for generating particles that perfectly resemble ambient particulate matters (PM) in terms of physical and chemical properties. The ambient PM samples were collected on filters using a high volume sampler; followed by their extraction in Milli-Q water. In an alternative approach, we captured the ambient PM samples directly into Milli-Q water using the versatile aerosol concentration enrichment system (VACES)/aerosol-into-liquid collector tandem technology. Commercial HOPE nebulizers were then implemented for re-aerosolizing aqueous PM slurries from these two approaches. To assess the physical properties of generated particles, their size distributions were investigated at different compressed air pressure of the nebulizer, and dilution flow rate by the means of a scanning mobility particle sizer (SMPS) in conjunction with a condensation particle counter (CPC). Moreover, chemical analysis were conducted on ambient, and re-aerosolized samples to determine their chemical components including elemental and organic carbon (EC/OC), water soluble organic carbon (WSOC), polycyclic aromatic hydrocarbons (PAHs), metals and trace elements, and inorganic ions. Our finding revealed that re-aerosolizing the aqueous extracted PM slurries will provide us with effective recovery of the water soluble constituents of ambient PM including water soluble organic matter, and water soluble inorganic ions. However, this approach is unable to recover water insoluble constituents of ambient PM such as EC, PAHs, and some of the redox-active metal elements. Conversely, re-aerosolizing the directly captured PM slurry collected via the means of VACES/aerosol-into-liquid collector tandem technology was able to perfectly reconstruct all constituents of ambient PM. Therefore, our results underscore the advantages of VACES/aerosol-into liquid collector tandem technology to collect aqueous slurries of ambient PM; followed by their re-aerosolization to generate stable aerosols that are well representative of ambient PM.