1. VOLATILITY MEASUREMENTS OFF LABORATORY GENERATED ORGANIC AEROSOLS WITH VOLATILITY TANDEM DIFFERENTIALLY MOBILITY ANALYZER. VTDMA K. Salo*, Å. M. Jonsson, P. U. Andersson and M. Hallquist Department of Chemistry, Atmospheric Science,Göteborg University, Sweden *kent.salo@chem.gu.se

2. Outline Background Secondary Organic Aerosols Analyze methods Results Other work Summary

3. Background Coarse particles cause Lung an respiratory diseases. Fine particles cause increased cardiovascular mortality. Aerosols affect earths radiation budget. Alters cloud properties. Possible effect on formation of precipitation. HealthClimate

4. Background Example of aerosol Constituents.

5. Secondary Organic Aerosols Many different reactive Volatile Organic Compounds (VOC) are emitted from biogenic sources. Ref from: Goldstein et al. 2007

6. Analyze methods Scanning mobility particle sizer (SMPS). DMA CPC

7. Analyze methods Compressed Dry clean air Dilution volume Silica diffusion dryer Aqueous sample solution DMA 1 TSI 3071 HEPA Filter Pump TSI 3071 Aerosol generator Aqueous sample Silica diffusion dryer Char coal Filter RH monitor Oven3 Oven 4 Oven 1 Oven 2 SMPS TSI 3096 Scrubber

8. Analyze methods

11. Results Volume Fraction Remaining (VFR) of selected Organic and inorganic compounds.

12. Results Mixtures of dicarboxylic acid/ammonium sulphate.

13. Results Mixtures of dicarboxylic acid.

14. Results Assumptions: 1.Spherical particles 2.Surface free energy isotropic. 3.Neglected latent heat effects. 4.Partial pressure of evaporating species negligible. J. Mönster et al. 2004.

15. Results Assuming Clausius-Clapeyron relationship between vapor pressure and temperature. ΔH vap/sub can be inferred From linear least squares analysis. J. Mönster et al. 2004.

16. Results Glutaric acid

17. Results Pimelic acid

18. Results Physical properties of used dicarboxylic acid (results and litterature data)

19. Results Heat transfer resistance problem?

20. Results P 0 independent of residence time.

21. Results No saturation, independent of mass load

22. Results

24. Other work G-FROST G-FROST Göteborg- Flow Reactor for Oxidation Studies at low Temperatures Temperature range: 243-325K RH: GORE-TEX® Terpene: Diffusion vial OH-scavenger: wash bottle

25. Other work

26. Limone, 2-butanol, ozone at 10 % RH. SOA conc. From 4 – 20 μg/m 3

27. Summary The VTDMA is proved to be an efficient and useful tool to analyze the volatility properties and vapour pressures of different aerosol particles. The volatility (evaporation rates), heat of vaporization (ΔHvap) and vapour pressures obtained in this work is generally in line with earlier published results obtained from VTDMA experiments and other methods. Knowledge obtained from experiments with pure substances and simple mixtures makes it possible to evaluate more complex systems.

28. Summary Water effect on SOA formation from monoterpenes. Possible effect on volatility. Clear masseffect on SOA volatility properties. Positive, Negative?

29. The End