Public Research Seminar by Earth, Ocean and Atmospheric Sciences (EOAS) Thrust, HKUST (GZ) - Novel analytical concepts for addressing the composition as well as the climate- and health-impact of airborne particulate matter (PM)
Air pollution by fine particle matter (PM) is known to be the most severe environmental health-risks worldwide (WHO, 2001) and has large climate impact. The investigation of adverse effect mechanisms of aerosols including the impact of the organic PM fraction is a complex task with many scientific and technological challenges. New analytical methods and scientific instruments for an effect-directed characterization of the chemical composition as well as important physical properties of aerosol particles (e.g., the internal/external mixing state of toxicants within the particle ensemble, optical properties, better source apportionment approaches) can help to better fulfill this task. In addition, biological approaches for investigation the adverse toxic effects of aerosols are needed. In this context, new analytical approaches for both, the organic chemical and the toxicological characterization of aerosols are presented, discussed and demonstrated. In particular, rapid aerosol characterization methods based on Photo Ionization Mass Spectrometry (PIMS) are introduced. Photo Ionization (PI) is well suited to address the pattern of the highly health relevant Polycyclic Aromatic Hydrocarbons (PAH). One approach is to analyze the PAH and other compounds evolving from a PM-loaded filter punch during a thermal-optical carbon analysis (i.e., an EC/OC measurement). For this a EC/OC-TOCA system (DRI 2025 by Aerosol-Magee) is hyphenated to a Photoionization Mass Spectrometer (PhotoTOF by Photonion). The technology is introduced and application examples are given. For on-line measurements a novel improved Single Particle Mass Spectrometer (SPMS) has been developed. This system allows the real-time measurement and mixing-state analysis for inorganic compounds (metals/soot/salts/minerals) as well as for organic compounds (PAH, oxalate etc.) on single aerosol particle basis, by using resonance ionization processes (Application examples of wildfire aerosol and ship emissions are presented. Finally, an improved methodology to directly assess the toxicological impact of aerosols by air-liquid-interface (ALI) exposure of human lung cell-cultures is discussed.
Ralf Zimmermann is full professor of Analytical Chemistry at the University of Rostock and director of the research unit CMA at the Helmholtz Centre Munich. Furthermore, he is the speaker of the Department Life, Light & Matter of the Interdisciplinary Faculty of the University of Rostock and is heading the Competence Center for Mass Spectrometry in the Department. He studied Chemistry and Physics and holds a PhD degree in Physical/Analytical Chemistry. Among others activities his primary methodological research interest lies in the development of novel (laser and photo-ionization) mass spectrometric methods and technologies for on-line characterization of aerosols, ambient particulate matter, process gases as well as combustion and pyrolysis emissions. This research led to the co-founding of the spin-off company Photonion GmbH in 2009. Prof. Zimmermann also performs method development for the comprehensive characterization of ultra-complex molecular systems, using e.g., high resolution mass spectrometric technologies, thermal analysis as well as multidimensional separation approaches, combined with chemometric approaches. His applicative research is focusing on the holistic, interdisciplinary investigation of the composition, atmospheric processing, toxicology and health impact of ambient aerosols and combustion emissions. In this context he is studying the impact of biogenic and anthropogenic aerosol sources, e.g., the emissions from vegetation, wildfires, traffic (road, air, sea) or industrial activities.