100 Years of Photoionization; Unraveling Aerosol Complexity One Particle at a Time: Multidimensional Single Particle Characterization

Single Particle Mass Spectrometry (SPMS) has revolutionized aerosol science, enabling in-situ, real-time characterization of individual aerosol particles within complex and heterogeneous environments. This talk will briefly explore key advancements in photoionization over the past century—developments that have significantly enhanced the capabilities of modern SPMS by improving mass resolution, precision, and temporal response. These innovations enable the real-time acquisition of rich aerosol data and provide vital insights into dynamic processes such as particle formation, growth, and atmospheric evolution.
Aerosols, both natural and anthropogenic, are inherently heterogeneous and complex. Their impacts on air quality, human health, and Earth’s radiative balance depend on interrelated physicochemical properties such as particle concentration, composition, optical properties, cloud activation potential, and reactivity. Traditional ensemble-based methods average over mixtures of diverse particles, often masking the critical variability at the single-particle level. Overcoming these challenges requires the simultaneous analysis of multiple properties for individual particles—a capability uniquely achieved through our SPMS.
I will present our innovative approach to simultaneously measure a broad range of interconnected properties for the very same particles with exceptionally high sensitivity, temporal resolution, mass spectral quality, and sub-monolayer sizing precision. This multidimensional single-particle characterization enables the establishment of crucial links between aerosol properties, their behaviors, and their environmental impacts.
Finally, I will demonstrate the versatility of this approach across diverse applications, including the characterization of atmospheric aerosols, engineered nanoparticles, chemical warfare and pharmaceutical-based agents, and particles produced by combustion and detonation of high-energy explosives.