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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Characterization of trace metals on soot aerosol particles with the SP-AMS: detection and quantification

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Carbone, S. [1] ; Onasch, T. [2] ; Saarikoski, S. [1] ; Timonen, H. [1] ; Saarnio, K. [1] ; Sueper, D. [2, 3] ; Ronkko, T. [4] ; Pirjola, L. [5, 6] ; Hayrinen, A. [7] ; Worsnop, D. [5, 2, 1] ; Hillamo, R. [1]
Total Authors: 11
[1] Finnish Meteorol Inst, Atmospher Composit Res, FIN-00101 Helsinki - Finland
[2] Aerodyne Res Inc, Billerica, MA 01821 - USA
[3] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80303 - USA
[4] Tampere Univ Technol, Dept Phys, FIN-33101 Tampere - Finland
[5] Univ Helsinki, Dept Phys, FIN-00014 Helsinki - Finland
[6] Metropolia Univ Appl Sci, Helsinki - Finland
[7] Helen Ltd, Helsinki 00090 - Finland
Total Affiliations: 7
Document type: Journal article
Source: Atmospheric Measurement Techniques; v. 8, n. 11, p. 4803-4815, 2015.
Web of Science Citations: 14

A method to detect and quantify mass concentrations of trace metals on soot particles by the Aerodyne soot-particle aerosol mass spectrometer (SP-AMS) was developed and evaluated in this study. The generation of monodisperse Regal black (RB) test particles with trace amounts of 13 different metals (Na, Al, Ca, V, Cr, Mn, Fe, Ni, Cu, Zn, Rb, Sr and Ba) allowed for the determination of the relative ionization efficiency of each metal relative to black carbon (RIEmeas). The observed RIEmeas/RIEtheory values were larger than unity for Na, Rb, Ca, Sr and Ba due to thermal surface ionization (TSI) on the surface of the laser-heated RB particles. Values closer to unity were obtained for the transition metals Zn, Cu, V and Cr. Mn, Fe, and Ni presented the lowest RIEmeas/RIEtheory ratios and highest deviation from unity. The latter discrepancy is unexplained; however it may be related to problems with our calibration method and/or the formation of metal complexes that were not successfully quantified. The response of the metals to the laser power was investigated and the results indicated that a minimum pump laser current of 0.6 A was needed in order to vaporize the metals and the refractory black carbon (rBC). Isotopic patterns of metals were resolved from high-resolution mass spectra, and the mass-weighted size distributions for each individual metal ion were obtained using the high-resolution particle time-of-flight (HR-PToF) method. The RIEmeas values obtained in this study were applied to the data of emission measurements in a heavy-fuel-oil-fired heating station. Emission measurements revealed a large number of trace metals, including evidence for metal oxides and metallic salts, such as vanadium sulfate, calcium sulfate, iron sulfate and barium sulfate, which were identified in the SP-AMS high-resolution mass spectra. SP-AMS measurements of Ba, Fe, and V agreed with ICP-MS analyzed filter samples within a factor of 2 when emitted rBC mass loadings were elevated. (AU)

FAPESP's process: 14/05238-8 - Physical-chemical properties of biogenic secondary organic aerosols in the Amazon Forest
Grantee:Samara Carbone
Support type: Scholarships in Brazil - Post-Doctorate