Real-Time Study of Particle-Phase Products from α-Pinene Ozonolysis and Isoprene Photooxidation Using Particle into Liquid Sampling Directly Coupled to a Time-of-Flight Mass Spectrometer (PILS-ToF)

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 α-pinene dark ozonolysis and isoprene photooxidation. The characterization of the PILS-ToF system includes experiments on the well understood α-pinene/O3 system, which verifies the performance of the tool. The PILS-ToF tool is then used to provide new insight into the chemical composition of the SOA formed from isoprene photooxidation. For the first time, time ...