A41A-0044
Multi-Modal Spatial Analysis of Metals within Individual Aerosol Particles Sampled from the Asian Continental Outflow
Thursday, 17 December 2015
Poster Hall (Moscone South)
Ryan Moffet1, Tristan Harder2, Garth Williams3, Yu-chen K Chen-Wiegart4, Hiroshi Furutani5, Mary Kathleen Gilles6, Alexander Laskin7, Martin A. Schoonen3, Juergen Thieme3 and Mitsuo Uematsu8, (1)University of the Pacific, Stockton, CA, United States, (2)Lawrence Berkeley National Lab, Berkeley, CA, United States, (3)Brookhaven National Laboratory, Upton, NY, United States, (4)Brookhaven National Laboratory, Photon Sciences Directorate, Upton, NY, United States, (5)Osaka University, Center for Scientific Instrument Renovation and Manufacturing Support, Osaka, Japan, (6)Lawrence Berkeley National Laboratory, Berkeley, CA, United States, (7)Pacific North West National Laboratory, EMSL, Richland, WA, United States, (8)University of Tokyo, Bunkyo-ku, Japan
Abstract:
Aerosols represent an important source of iron and other metals into oceanic surface waters. In some regions of the ocean, the productivity is limited by iron. Thus, iron is an important variable in the carbon cycles of both marine and atmospheric environments. Here, we build upon previous work characterizing the source and oxidation state of iron in atmospheric particles to provide more information on the mineralogy of the iron phases using the newly built Sub-Micron Resolution X-ray Spectroscopy (SRX) beamline at the National Synchrotron Light Source II (NSLS II). The SRX beamline covers energies from 4.6 to 24 keV, allowing mapping of elements from Z=15 (P) to Z=95 (Am) at a sub-micrometer and a sub-100 nm spatial scale. This new method of aerosol analysis will provide outstanding performance for the spectromicroscopy of trace elements. Moreover, this technique will provide multiple modes of detection (fluorescence, absorption, diffraction, and tomographic imaging) to allow for a more complete characterization of the molecular nature of natural samples having nanometer scale structural features. Simultaneously measured X-ray absorption and fluorescence spectra from Asian mineral dust standards and deposited atmospheric particles will be presented. Application of this technique to atmospheric particle samples will broaden the scope of elements over which detailed spectral information can be obtained at a high spatial resolution and will complement existing imaging methods used to determine aerosol chemical and physical properties.
