AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Chemically Specific Online Removal of Submicron Aquadag Aerosol with the Single Particle Soot Photometer
ALLISON AIKEN, Gavin McMeeking, Manvendra Dubey, Paul DeMott, Ezra Levin, Los Alamos National Lab
Abstract Number: 709 Working Group: Instrumentation and Methods
Abstract The ability to separate black carbon (BC) from organic carbon (OC) in an online aerosol sample would enable the physical processes and optical properties to be studied by carbon class. We present a method to remove BC from an online aerosol sample, demonstrated with the soot surrogate Aquadag in the laboratory. This method could be applied to ambient and source aerosol samples to isolate the roles that different carbon classes have on climate, e.g. atmospheric warming, cloud formation and lifetime. A study was performed using two Single-Particle Soot Photometers (SP2s) in series, along with a Three-Wavelength Photoacoustic Soot Spectrometer (PASS-3) for measuring optical properties. Polydisperse and monodisperse Aquadag was sampled from 100 nm to 800 nm in diameter. Comparison of number, mass and optical properties of the Aquadag and the particles remaining after laser-induced incandescence (LII) are reported. For all monodisperse samples, the average percent remaining by mass and number of the original size selected are 11.1% ± 18.6% and 12.7% ± 21.9%, respectively. The results of this study are applicable to other instruments employing LII, e.g. the Soot Particle Aerosol Mass Spectrometer (SP-AMS), and could also potentially be used for the study of new and/or altered carbonaceous particles in a controlled environment.