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www.atmos-meas-tech-discuss.net/3/1775/2010/
doi:10.5194/amtd-3-1775-2010
© Author(s) 2010. This work is distributed
under the Creative Commons Attribution 3.0 License.
High time-resolution chemical characterization of the water-soluble fraction of ambient aerosols with PILS-TOC-IC and AMS
1Air Quality Research, Finnish Meteorological Institute, P.O. Box 503, 00101 Helsinki, Finland
2Department of Physics, University of Helsinki, P.O. Box 64, 00014 Helsinki, Finland
3Aerodyne Research, Inc., 45 Manning Road, Billerica, MA 01821-3976, USA
Abstract. A particle-into-liquid sampler (PILS) was coupled with a total organic carbon analyzer (TOC) and two ion chromatographs (IC) to enable high time-resolution measurements of water-soluble ions and water-soluble organic carbon (WSOC) by a single sampling and analytical set-up. The new high time-resolution measurement system, the PILS-TOC-IC, was able to provide essential chemical and physical information about fast changes in composition, concentrations and likely sources of the water-soluble fraction of atmospheric aerosol. The concentrations of major water-soluble ions and WSOC were measured by the PILS-TOC-IC system from 25 April to 28 May 2009. The data of the PILS-TOC-IC setup was completed with the data from the High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) data measured from 25 April to 8 May 2009. The measured water-soluble particulate organic matter (WSPOM) concentration varied typically from 0.10 to 8.8 µg m−3 (on average 1.5 µg m−3). The WSPOM contributed on average 51% to particulate organic matter (POM) measured with the AMS. The correlation between the data of all the online measurement devices (AMS, PILS-TOC-IC, semicontinous EC/OC carbon analyzer and TEOM) was excellent. For sulfate, nitrate and ammonium the correlations between the PILS-TOC-IC and AMS were 0.93, 0.96 and 0.96, respectively. The correlation between WSPOM and POM was also strong (r=0.88).
The identified sources of WSPOM were long-range transported biomass burning and secondary organic aerosol (SOA) formation. The WSPOM/POM-ratio followed the trends of the ambient daytime temperature. The temperature dependency of the WSPOM/POM-ratio suggest that in the absence of emissions from biomass burning, the SOA formation was the prevailing source for WSPOM. WSPOM produced in biomass burning was clearly correlated with carbon monoxide, confirming that biomass burning was producing primary WSPOM. In addition, elevated oxalate and potassium concentrations were measured during the biomass burning episode.
Discussion Paper (PDF, 3804 KB) Interactive Discussion (Closed, 4 Comments) Final Revised Paper (AMT)
Notice on Discussion StatusCitation: Timonen, H., Aurela, M., Carbone, S., Saarnio, K., Saarikoski, S., Mäkelä, T., Worsnop, D. R., Kulmala, M., Kerminen, V.-M., and Hillamo, R.: High time-resolution chemical characterization of the water-soluble fraction of ambient aerosols with PILS-TOC-IC and AMS, Atmos. Meas. Tech. Discuss., 3, 1775-1805, doi:10.5194/amtd-3-1775-2010, 2010. Bibtex EndNote Reference Manager XML
