AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Advanced Analysis Procedures of Ambient Organic Aerosol from Thermal Desorption – Mass Spectrometry Measurement Techniques
YAPING ZHANG, Brent Williams, Raul Martinez, Manjula Canagaratna, Douglas Worsnop, Allen H. Goldstein, Ingrid Ulbrich, Donna Sueper, Jose-Luis Jimenez, Washington University in St. Louis
Abstract Number: 475 Working Group: Instrumentation and Methods
Abstract The feasibility of a simplified method to analyze thermal desorption aerosol gas chromatography (TAG) data was investigated. Chromatograms were divided into many “volatility” bins containing total eluting mass (both unresolved complex mixture (UCM) and resolved species). Positive Matrix Factorization (PMF), a factor analysis technique, was applied to compare the results between bin-based and peak-integrated methods using the TAG data in 2005 Study of Organic Aerosol at Riverside (SOAR). We found the procedure of bin-based method to take only a small fraction of the time to complete compared to peak-integrated method, significantly saving the operator time and effort. Many factors in the peak-integrated method had good correlations (R>0.5) with factors in the bin-based method. Here we explore the differences and similarities amongst our results. The bin-based method is a promising method of rapid analysis for chromatography data for the purpose of source apportionment and transformation mechanisms of atmospheric aerosols.
Additionally, automated preprocessing and analysis procedures for a new thermal desorption-mass spectrometery technique, volatility and polarity separator (VAPS), has been explored. IGOR software was used as the platform of the procedure. The automated preprocessing procedures contain auto retention time shifting, auto binning of volatility and polarity, auto internal standards mass calibration, and auto error matrix calculation and PMF export. Four datasets — simulated VAPS data, 15 mixture standards, biomass burning aerosol from custom combustion chamber, and ambient atmospheric data collected on the campus of Washington University in St. Louis — were tested through the automated preprocessing and analysis procedures. It has been proven to be an effective method for fully automated analysis and interpretation of VAPS data.