Chemical Characterization by Particle into Liquid Sampling Directly Coupled to an Accurate Mass Time-of-Flight Mass Spectrometer (PILS-ToF) of Secondary Organic Aerosol (SOA)

Christopher H. Clark (1,2), Shunsuke Nakao (1,2), Kei Sato(3), Li Qi(1,2), Akua Asa-Awuku(1,2), David R. Cocker, III (1,2)

(1) University of California–Riverside, College of Engineering–Center for Environmental Research and Technology (CE–CERT), (2) University of California–Riverside, Department of Chemical and Environmental Engineering (3) Asian Environment Research Group, National Institute for Environmental Studies, Ibaraki, Japan

     Abstract Number: 732
     Last modified: May 14, 2010

Abstract
A particle into liquid sampler (PILS) has been directly coupled to an accurate mass atmospheric ionization time-of-flight mass spectrometer (ToF) for use in the speciation of secondary organic aerosol (SOA) formed in the University of California, Riverside, College of Engineering, Center for Environmental Research and Technology (CE-CERT) atmospheric chambers. To this end, the PILS has been optimized for direct continuous injection into the ToF and the PILS-ToF system has been used to obtain real-time mass spectral traces of the particle phase products of atmospheric chamber reactions. The PILS-ToF system has been initially applied to SOA formed from alpha-pinene dark ozonolysis and isoprene photo-oxidation. The characterization of the PILS-ToF system is presented including performance on the well understood alpha-pinene/O3 system which verified the performance of the tool and the study of the SOA formed in the photo-oxidation of isoprene is also presented. Additionally, the PILS-ToF has provided real-time traces of oligomer products in isoprene photo-oxidation, as reported by Surratt et al. (2006), while also providing new insight into possible particle-phase intermediates. Testing and preliminary experimentation indicate that the PILS-ToF system is an excellent tool for obtaining real-time electro spray ionization and chemical ionization mass spectral speciation of aerosols. The real-time characterization of particle phase products allows kinetic study of SOA particle phase reactions.