PhD in Atmospheric Environmental Science - Organosulfates in Atmospheric Aerosols: Synthesis, Quantification, Ambient abundance and Insights into formation mechanism
9:30am - 10:30am
Room 2406 (Lifts 17-18) 2/F Academic Building
Organosulfates (OSs) derived from biogenic volatile organic compounds (BVOCs) represent an important class of products formed between anthropogenic sulfur pollution and natural emissions. Both smog-chamber studies and ambient aerosol measurements have shown these organosulfates may contribute a significant part of secondary organic aerosol (SOA). However, a lack of authentic OS standards and a systematic study of distribution of OSs under different polluted conditions in ambient samples presents significant obstacles to our quantitative understanding of this chemical interaction between human and nature. Work in this thesis aims to improve the scientific understanding of factors controlling ambient abundance and composition, and to gain more insights into formation mechanism of OSs, with a special emphasis on the aerosols of China. This thesis work is the first study reporting the synthesis methods and accurate abundance of a full range of -hydroxy terpene OS and terpene NOSs. With the help of authentic standards, this work provides some guidelines for selecting surrogates in LC/MS analysis for OS compounds when standards are not commercially available. This work has identified some possible intermediates in the OSs formation mechanism, which provides valuable leads for future chamber studies. In addition, a field study employing both real-time measurement of gas- and particle-phase OSs and off-line filter-based OS measurements provides an example of illustrating the importance of having authentic standards for on-line instrumental method development. Finally, contrasting OS measurements in samples from three climatic zones in China reveals the complexity of the web of factors that affect the interactions between biogenic VOC emissions and anthropogenic pollution.
Event Format
Thesis Defense
Candidate
Ms. WANG Yuchen
Language
English
Recommended For
Faculty and staff
PG students
Contact
Should you have any questions, please feel free to contact ENVR at envr@ust.hk.