Abstract View
Measurement of Aerosol Volatility Using a Modified Piezoelectric Instrument
LANCE WALLACE, Wayne Ott, Stanford University
Abstract Number: 658
Working Group: Indoor Aerosols
Abstract
Collection of an aerosol on a filter and then weighing the filter is often called the “gold standard” for determining the mass of the collected aerosol. Yet if the aerosol is volatile, a portion will evaporate from the filter during collection. For example, an important component of PM2.5, particularly in the West, is ammonium nitrate, which can account for a substantial fraction of the mass. A more recently popular example of a volatile aerosol is the secondhand aerosol produced by vaping electronic cigarettes and, possibly, by vaping marijuana liquids1. The cited reference employed 40-year-old Piezobalances (Kanomax, Japan) that had been modified to report and log the frequency differences as well as mass concentrations in each time step. When the frequency difference turns negative, it indicates evaporation from the crystal. However, the standard Piezobalance shows only concentrations and thus cannot measure the loss due to evaporation. However, in response to a letter from a number of scientists asking Kanomax to make available some instruments modified to report frequency differences, it has just been learned (May 2021) that Kanomax will make such modifications upon request of buyers. This presentation will explain how to use the newly modified instruments to measure volatility of selected aerosols.
[1] Wallace, L.A., Ott, W.R., Zhao, T., Cheng, K-C, and Hildemann, L.M. 2021 Method for estimating the volatility of aerosols using the Piezobalance: examples from vaping e-cigarette and marijuana liquids. Atmospheric Environment Volume 253, 15 May 2021, 118379. https://doi.org/10.1016/j.atmosenv.2021.118379