10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Comparison between ACSM and AMS at an Urban Site in Atlanta, GA: The Use of Capture Vaporizer and PM2.5 Inlet
TAEKYU JOO, Weiqi Xu, Masayuki Takeuchi, Gamze Eris, Yunle Chen, Dao Huang, Gabriela Saavedra, Seongshik Kim, Dong Gao, Rodney J. Weber, Yele Sun, Philip Croteau, John Jayne, Nga Lee Ng, Georgia Institute of Technology
Abstract Number: 1129 Working Group: Instrumentation
Abstract Aerosol Mass Spectrometer (AMS) and Aerosol Chemical Speciation Monitor (ACSM) are widely used to quantify non-refractory aerosol composition. Standard vaporizers (SV) with PM1 aerodynamic lenses are installed in most of current AMS or ACSM instruments. While particles can bounce off from SV and decrease particle collection efficiency (CE), the new capture vaporizer (CV) has been developed and typically shows a CE of ~1 in ambient measurements. Compared to SV, CV also maintains a high CE for larger particles, which makes it possible to measure up to the PM2.5 size range. To investigate differences in aerosol composition between the 1μm and 2.5μm size fractions in the atmosphere, a PM1 SV-AMS and a PM2.5 CV-ACSM were deployed at the Jefferson Street site in Atlanta, which is an urban site in the Southeastern Aerosol Characterization (SEARCH) network. Two measurement campaigns were conducted, one in summer 2017 and one in winter 2018. Aerosol volume concentration data estimated from AMS, ACSM and SUNSET OC/EC Analyzer was compared to the data from a Scanning Mobility Particle Sizer (SMPS). Positive matrix factorization (PMF) analyses were performed on ACSM and AMS data and results were compared. The differences between SV-AMS and CV-ACSM were also characterized through photo-oxidation experiments of α-pinene and β-pinene in the Georgia Tech Environmental Chamber (GTEC) facility. Organic fragmentation patterns of SV-AMS and CV-ACSM were identified from the chamber experiments.