10.6084/m9.figshare.942507.v3 Brent J. Williams Brent J. Williams John T. Jayne John T. Jayne Andrew T. Lambe Andrew T. Lambe Thorsten Hohaus Thorsten Hohaus Joel R. Kimmel Joel R. Kimmel Donna Sueper Donna Sueper William Brooks William Brooks Leah R. Williams Leah R. Williams Achim M. Trimborn Achim M. Trimborn Raul E. Martinez Raul E. Martinez Patrick L. Hayes Patrick L. Hayes Jose L. Jimenez Jose L. Jimenez Nathan M. Kreisberg Nathan M. Kreisberg Susanne V. Hering Susanne V. Hering David R. Worton David R. Worton Allen H. Goldstein Allen H. Goldstein Douglas R. Worsnop Douglas R. Worsnop The First Combined Thermal Desorption Aerosol Gas Chromatograph—Aerosol Mass Spectrometer (TAG-AMS) Taylor & Francis Group 2014 thermal desorption aerosol spectrometer 2014-03-21 15:58:34 Journal contribution https://tandf.figshare.com/articles/journal_contribution/The_First_Combined_Thermal_Desorption_Aerosol_Gas_Chromatograph_8212_Aerosol_Mass_Spectrometer_TAG_AMS_/942507 <div><p>To address the critical need for improving the chemical characterization of the organic composition of ambient particulate matter, we introduce a combined thermal desorption aerosol gas chromatograph—aerosol mass spectrometer (TAG-AMS). The TAG system provides <i>in-situ</i> speciation of organic chemicals in ambient aerosol particles with hourly time resolution for marker compounds indicative of sources and transformation processes. However, by itself the TAG cannot separate by particle size and it typically speciates and quantifies only a fraction of the organic aerosol (OA) mass. The AMS is a real-time, <i>in-situ</i> instrument that provides quantitative size distributions and mass loadings for ambient fine OA and major inorganic fractions; however, by itself the AMS has limited ability for identification of individual organic compounds due to the electron impact ionization detection scheme used without prior molecular separation.</p> <p>The combined TAG-AMS system provides real-time detection by AMS followed by semicontinuous analysis of the TAG sample that was acquired during AMS operation, achieving simultaneous and complementary measurements of quantitative organic mass loading and detailed organic speciation. We have employed a high-resolution time-of-flight mass spectrometer (HR-ToF-MS) to enable elemental-level determination of OA oxidation state as measured on the AMS, and to allow improved compound identification and separation of unresolved complex mixtures (UCM) measured on the TAG. The TAG-AMS interface has been developed as an upgrade for existing AMS systems. Such measurements will improve the identification of organic constituents of ambient aerosol and contribute to the ability of atmospheric chemistry models to predict ambient aerosol composition and loadings.</p> <p>Copyright 2014 American Association for Aerosol Research</p> </div>