Articles | Volume 9, issue 1
Atmos. Meas. Tech., 9, 23–39, 2016
Atmos. Meas. Tech., 9, 23–39, 2016

Research article 15 Jan 2016

Research article | 15 Jan 2016

Characterization and source apportionment of organic aerosol using offline aerosol mass spectrometry

K. R. Daellenbach1, C. Bozzetti1, A. Křepelová1, F. Canonaco1, R. Wolf1, P. Zotter1,a, P. Fermo4, M. Crippa1,b, J. G. Slowik1, Y. Sosedova1, Y. Zhang1,2,3,c, R.-J. Huang1, L. Poulain5, S. Szidat2, U. Baltensperger1, I. El Haddad1, and A. S. H. Prévôt1 K. R. Daellenbach et al.
  • 1Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
  • 2Department of Chemistry and Biochemistry & Oeschger Centre for Climate Change Research, University of Bern, 3012 Bern, Switzerland
  • 3Laboratory of Radiochemistry and Environmental Chemistry, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
  • 4Department of Chemistry, University of Milan, 20133 Milan, Italy
  • 5Leibniz Institute for Troposphärenforschung, Leipzig, Germany
  • anow at: Lucerne School of Engineering and Architecture, Bioenergy Research, Lucerne University of Applied Sciences and Arts, 6048 Horw, Switzerland
  • bnow at: EC Joint Research Centre, Institute for Environment and Sustainability, 21027 Ispra, Italy
  • cnow at: Yale-NUIST Center on Atmospheric Environment, Nanjing University of Information Science and Technology, Nanjing 10044, China

Abstract. Field deployments of the Aerodyne Aerosol Mass Spectrometer (AMS) have significantly advanced real-time measurements and source apportionment of non-refractory particulate matter. However, the cost and complex maintenance requirements of the AMS make its deployment at sufficient sites to determine regional characteristics impractical. Furthermore, the negligible transmission efficiency of the AMS inlet for supermicron particles significantly limits the characterization of their chemical nature and contributing sources. In this study, we utilize the AMS to characterize the water-soluble organic fingerprint of ambient particles collected onto conventional quartz filters, which are routinely sampled at many air quality sites. The method was applied to 256 particulate matter (PM) filter samples (PM1, PM2.5, and PM10, i.e., PM with aerodynamic diameters smaller than 1, 2.5, and 10 µm, respectively), collected at 16 urban and rural sites during summer and winter. We show that the results obtained by the present technique compare well with those from co-located online measurements, e.g., AMS or Aerosol Chemical Speciation Monitor (ACSM). The bulk recoveries of organic aerosol (60–91 %) achieved using this technique, together with low detection limits (0.8 µg of organic aerosol on the analyzed filter fraction) allow its application to environmental samples. We will discuss the recovery variability of individual hydrocarbon ions, ions containing oxygen, and other ions. The performance of such data in source apportionment is assessed in comparison to ACSM data. Recoveries of organic components related to different sources as traffic, wood burning, and secondary organic aerosol are presented. This technique, while subjected to the limitations inherent to filter-based measurements (e.g., filter artifacts and limited time resolution) may be used to enhance the AMS capabilities in measuring size-fractionated, spatially resolved long-term data sets.

Short summary
In this study, we developed an offline technique using the AMS for the characterization of the chemical fingerprints of aerosols collected on quartz filters, and evaluated the suitability of the organic mass spectral data for source apportionment. This technique may be used to enhance the AMS capabilities in measuring size-fractionated, spatially resolved long-term data sets.