ISSAOS 2008 l‘Aquila, September 2008 Aerosol Mass Spectrometry: The Aerosol mass Spectrometer

1. ISSAOS 2008 l‘Aquila, September 2008 Aerosol Mass Spectrometry: The Aerosol mass Spectrometer Hugh Coe School of Earth, Atmospheric and Environmental Sciences University of Manchester Reading: • D Murphy, The design of single particle laser mass spectrometers, in: Mass Spectrometry Reviews, 2007, 26, 150-165. • M. R. Canagaratna et al., Chemical and microphysical characterisation of ambient aerosols with the Aerodyne Aerosol Mass Spectrometer in: Mass Spectrometry Reviews, 2007, 26, 185-222. • H. Coe and J. D. Allan, “Aerosol Mass Spectrometry” in “Atmospheric techniques” ed D. E. Heard, Blackwell Scientific Publishing, 2006 • http://cires.colorado.edu/jimenez/ams-papers.html

2. Aerodyne Aerosol Mass Spectrometer (AMS) http://cires.colorado.edu/jimenez/ams-papers.html Particle Particle Beam Aerodynamic Sizing Composition Generation Quadrupole Mass Spectrometer Chopper Thermal Vaporization & Electron Impact Ionization TOF Region Aerodynamic Lens (2 Torr) Turbo Pump Turbo Pump Turbo Pump Particle Inlet (1 atm) 100% transmission (30-600 nm), aerodynamic sizing, linear mass signal. Development of an Aerosol Mass Spectrometer for Size and Composition Analysis of Sub-micron Particles. Jayne et al., Aerosol Science and Technology 33:1-2(49-70), 2000.

3. Flash Vaporization of Volatiles and Semi-Volatiles Electron Emitting Filament Focused Particle Beam e- Oven 500 C R+ Electron Impact Ionization AMS Detection Process Separation of Vaporization/Ionization allows for Quantitative Measurements Universal and quantitative chemical analysis: 0.1mg/m3 sensitivity. Vaporization and analysis of most aerosol chemical constituents - with primary exception of crustal oxides and elemental carbon.

4. Calibration & Experimental Set up…

5. Quantification of Aerosol Mass…(Jimenez et al., 2003) General Formula.. Nitrate Mass loading.. IE Ionisation Efficiency NA Avogadro’s number Q flow rate I ion rate MW molecular weight C mass concentration

6. Electron Impact a well defined ionisation

7. Quantification of Aerosol Mass… So the Mass loading of component s is.. IE Ionisation Efficiency NA Avogadro’s number Q flow rate I ion rate MW molecular weight C mass concentration RIE relative ionisation efficiency

8. Quantification of Aerosol Mass… Allan JD, Delia AE, Coe H, Bower KN, Alfarra MR, Jimenez JL, Middlebrook AM, Drewnick F, Onasch TB, Canagaratna MR, Jayne JT, Worsnop DR. 2004b. A generalised method for the extraction of chemically resolved mass spectra from Aerodyne aerosol mass spectrometer data. J Aerosol Sci 35:909–922, doi:910.1016/j.jaerosci. 2004.1002.1007.

9. This is what we measure……… Alfarra MR, Coe H, Allan JD, Bower KN, Boudries H, Canagaratna MR, Jimenez JL, Jayne JT, Garforth A, Li S-M, Worsnop DR. 2004. CHARACTERIZATION OF AMBIENT AEROSOLS WITH AN AEROSOL MASS SPECTROMETER & Mass Spectrometry Reviews DOI 10.1002/mas 217 Characterization of urban and regional organic aerosols in the lower Fraser Valley using two Aerodyne Aerosol Mass Spectrometers. Atmos Environ 38:5745–5758.

10. Aerodyne Aerosol Mass Spectrometer (AMS) http://cires.colorado.edu/jimenez/ams-papers.html Particle Particle Beam Aerodynamic Sizing Composition Generation Quadrupole Mass Spectrometer Chopper Thermal Vaporization & Electron Impact Ionization TOF Region Aerodynamic Lens (2 Torr) Turbo Pump Turbo Pump Turbo Pump Particle Inlet (1 atm) 100% transmission (30-600 nm), aerodynamic sizing, linear mass signal. Development of an Aerosol Mass Spectrometer for Size and Composition Analysis of Sub-micron Particles. Jayne et al., Aerosol Science and Technology 33:1-2(49-70), 2000.

11. Aerodynamic Particle Focusing Predicted and Measured Particle Collection Efficiency Particle Velocity Calibration

12. Example of AMS Output Organics Sulphate Nitrate Ammonium

13. Example of AMS Output Organics Sulphate Nitrate Ammonium

14. Example of AMS Output Organics Sulphate Nitrate Ammonium

15. Collection Efficiency (CE) Matthew, B.M., T.B. Onasch, and A.M. Middlebrook. Collection Efficiencies in an Aerodyne Aerosol Mass Spectrometer as a Function of Particle Phase for Laboratory Generated Aerosols. Aerosol Science and Technology, In press, July 2008. Takegawa, N., Y. Miyazaki, Y. Kondo, Y. Komazaki, T. Miyakawa, J.L. Jimenez, J.T. Jayne, D.R. Worsnop, J. Allan, and R. J. Weber (2005), Characterization of an Aerodyne Aerosol Mass Spectrometer (AMS): Intercomparison with other Aerosol Instruments, Aerosol Science and Technology, 39, 760-770, 2005

16. Quantification of Aerosol Mass… Including the CE, the Mass loading of component s is.. IE Ionisation Efficiency NA Avogadro’s number Q flow rate I ion rate MW molecular weight C mass concentration RIE relative IE CE collection efficiency

17. Understanding Organic Aerosols – Zhang et al., 2005

18. Understanding Organic Aerosols – Zhang et al., 2005

19. Understanding Organic Aerosols – Zhang et al., 2005 A factor analysis of the time series of organic mass spectra……

20. Extended to Positive Matrix Factorisation (PMF)

22. Evidence for OOA being a Secondary Photochemical Product Data from Gaffney, Marley, Brune, Volkamer, Cardenas et al. Mexico City April 9, 2003 Volkamer, Jimenez, et al., GRL, 2006.

23. Increase in SOA with residence time in atmosphere – observations much greater than models DeGouw et al. Johnson et al. Heald et al. Volkamer, Jimenez, et al., GRL, 2006. • Much higher SOA than predicted with current models • Discrepancy appears to increase with time

24. A Compact Time of Flight AMS Data from Shane Murphy Caltech

25. A High resolution time of Flight AMS

26. The Ability to resolve atomic composition

27. The Ability to resolve atomic composition

28. Ambient aerosol is much more oxygenated than chamber aerosol

29. Something for the future…… SP2-AMS schematic

30. Oil Lamp Soot Particles Obtain chemical information on elemental carbon clusters and organic compounds coating the soot cores