Comparison of Thermal and Non-Thermal Protocols for Analysis of Isoprene Secondary Organic Aerosol (SOA) Generated under Conditions of Low Nitrogen Oxides (NOx)

University Of North Carolina At Chapel Hill, Chapel Hill NC

Investigators

Abstract

This project is focused on laboratory studies of the formation of secondary organic aerosol (SOA) in the atmosphere derived from the presence of isoprene. Isoprene is a compound produced and emitted by many species of trees and other plant materials. Experiments will be conducted in a laboratory chamber to investigate the formation of SOA and assess the possible presence of artifacts related to the use of certain experimental methods. This study includes an in-depth, quantitative, molecular-level investigation of isoprene-SOA composition and aging. The objectives of the research are to: (1) synthesize standards to investigate artifact formation and to identify labile components degraded during conventional thermal GC-ESI/MS analysis of isoprene SOA formed under low-nitrogen oxide (NOx) conditions; (2) optimize hydrophilic interaction liquid chromatography (HILIC) protocols for separation of synthetic targets and SOA extracts; and (3) conduct an analysis of the SOA particles and identification of analytical artifacts/decomposition products by comparison of results from HILIC and GC/EI-MS protocols. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.