Elemental ratio measurements of organic compounds using aerosol mass spectrometry: characterization, improved calibration, and implications

Abstract. Elemental compositions of organic aerosol (OA) particles provide useful constraints on OA sources, chemical evolution, and effects. The Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) is widely used to measure OA elemental composition. This study evaluates AMS measurements of atomic oxygen-to-carbon (O : C), hydrogen-to-carbon (H : C), and organic mass-to-organic carbon (OM : OC) ratios, and of carbon oxidation state (OS C) for a vastly expanded laboratory data set of multifunctional oxidized OA standards. For the expanded standard data set, the method introduced by Aiken et al. (2008), which uses experimentally measured ion intensities at all ions to determine…

• NS
  National Science Foundation

  Awards: AGS1136479, ATM- 1238109, 1012809, AGS-1136479, 1243354, CHE-1012809, DE-AC02-05CH11231, 1238109, AGS-1243354
• UD
  U.S. Department of Energy

  Awards: -AC02-05CH11231, FG02-05ER84269, NOAA NA13OAR4310063, 05CH11231, DE-FG02-07ER84890, FG02-07ER84890, AC02-05CH11231, DE-AC02, DE-FG02-, DE-AC02-05CH11231, FG02-03ER83599, DE-FG02, DE-AC02-
• NA
  National Aeronautics and Space Administration

  Awards: DE-AC02-05CH11231, NNX12AC03G
• NO
  National Oceanic and Atmospheric Administration

  Award: NA13OAR4310063
• OO
  Office of Science

  Awards: AC02-05CH11231, -AC02-05CH11231, DE-AC02
• DO
  Division of Chemistry

  Awards: DE-AC02-05CH11231, CHE-1012809
• BE
  Basic Energy Sciences

  Awards: DE-AC02, AC02-05CH11231, DE-AC02-05CH11231, DE-FG02, -AC02-05CH11231