Understanding the chemistry of atmospheric particles using single particle mass spectrometry
Author(s)
Zawadowicz, Maria Anna
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Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences.
Advisor
Daniel J. Cziczo.
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This thesis explores ways in which single particle mass spectrometry can be extended, whether through hardware improvements, or through the use of advanced data processing techniques to provide new kinds of aerosol chemistry measurements. Most of this work has been carried out using the Particle Analysis by Laser Mass Spectrometry (PALMS) instrument, an aircraft deployable mass spectrometer that uses intense (~10 9 Wcm -2 ) UV laser pulses to vaporize and ionize single particles and measures their mass spectra using a time-of-flight mass spectrometer. Near-term and long-term hardware improvements as well as advanced data analysis techniques are explored in order to extract new chemical information from the thus obtained single particle mass spectra. Hardware improvements to PALMS are explored, such as the use of a high-powered femtosecond laser to obtain single particle mass spectra and a new high resolution compact mass analyzer. Also, a new commercial mass spectrometer LAAPToF is characterized and compared to PALMS. In addition to hardware improvements, novel data analysis techniques for analysis of single particle mass spectra were developed as a part of this work. In particular, a new method to identify biologically-derived particles is presented and used to derive vertical profiles of bioaerosol from near-surface to the upper troposphere.
Description
Thesis: Ph. D. in Atmospheric Chemistry, Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2017. Cataloged from PDF version of thesis. Includes bibliographical references (pages 197-219).
Date issued
2017Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary SciencesPublisher
Massachusetts Institute of Technology
Keywords
Earth, Atmospheric, and Planetary Sciences.