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Carbon Isotopic Compositions of PM: Constraints on their Emission Sources and Formation Process

Environment Environnement Canada Canada. Carbon Isotopic Compositions of PM: Constraints on their Emission Sources and Formation Process. • Regional Air Quality • Global Climate Change.

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Carbon Isotopic Compositions of PM: Constraints on their Emission Sources and Formation Process

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  1. Environment Environnement Canada Canada Carbon Isotopic Compositions of PM: Constraints on their Emission Sources and Formation Process •Regional Air Quality • Global Climate Change Distribution of sources (i.e. anthropogenic and natural) & formation processes (primary and secondary) are not well understood For AQRB Branch Mid-Term Review (Oct. 25-27, 2004)

  2. Photochemical Oxidation of OCs = a * RS Anthropogenic Why measuring Isotopic Composition of PM Observation:RobSOM Sources d13Csourcei= (d13Cffi Fff)+ (d13Cbioi Fbio)+ (d13Cfirei Ffire) +(d13Cbgi Fbg)… d13C = [(Rsam/RStd) -1]*103, R = 13C/12C Plants

  3. Objectives • Developing an unique & reliable methodology • Determining isotope profiles from different sources • Understanding the distribution and impact of sources via measuring isotopic compositions of ambient air, from both background and urban area Team L. Huang, W. Zhang, A. Chivulescu, D. Ernst (AQRB) S. Irei (York U.) Collaborators J. Brook, S. Sharma (AQRB) Dr. Hans Moosmüller (Desert Research Institute, USA)

  4. Experimental Method

  5. -25.34 ± 0.43‰ -20.72 ± 0.26‰ 870°C 850°C -26.04 ± 0.36‰ 550°C 100ppm →1g/per punch More than 90% samples lie in the range of 1 – 40 g/ per punch Laser separation of OC from EC 100 % He 10 % O2 + 90% He Thermogram of OC/EC in Forest Sample

  6. Diesel (Q953) OC/EC ramping OC +CC EC3 870°C 870°C EC2 700°C OC4 EC1 OC3 550°C 500°C 450°C OC2 Laser separation of OC from EC 300°C OC1 150°C He O2 + He - 26.61 ± 0.44 ‰ (OC + CC) - 25.88 ± 0.35 ‰ (EC) 870°C 870°C - 26.04 ± 0.10 ‰ (OC) 550°C Laser separation of OC from EC He O2 + He Thermogram of OC/EC in Diesel Emission Diesel (Q953) OC/EC total

  7. Isotope compositions in Different Source Profiles and Ambient Air (Pacific 2001 Campaigns)

  8. Isotopic Compositions of Background Air Analytic precision : 0.3‰

  9. Carbon Isotopic Compositions of PM (OC/EC) from Bio-mass Burning and Their Source Materials Mean Std: < 0.2 ‰ C4 C3

  10. OC+CC EC3 870°C He O2 + He EC2 850°C - 32.91‰ (OC + CC) - 32.51‰ (EC) 700°C OC4 EC1 870°C 850°C OC3 550°C 500°C - 32.90 ‰ (OC) 450°C OC2 550°C 300°C OC1 150°C 100 % He Laser separation of OC from EC 10 % O2 + 90% He Secondary Organic Aerosols(Toluene reaction with OH-)

  11. PM 2.5 Analytic precision :<0.3‰ Carbon Isotopic Compositions in PM (Fraserdale, May - Aug. 2003) TSP TSP Analytic precision : <0.3‰

  12. O2 O2 He He Nafion Nafion Open Split Open Split Combustion Oven Combustion Oven Back Flush Back Flush Sample Sample 1078 1078 Injector Injector Finnigan Finnigan Data Data MAT 252 MAT 252 Acquisition Acquisition Varian Star 3600 GC Varian Star 3600 GC Ave. Std: ~ 0.5‰ Method Development (Isotope Measurements of n-Alkanes)  Oxygen level  Temp. of combustion  Accuracy: ~ 0.5 ‰ precision:~ 0.5 ‰ linearity:1– 50 ng

  13. Isotope Measurements of Individual Compounds (e.g. n-Alaknes) Accuracy & precision of the method: ~ 0.5‰

  14. Measurement artifact 2-Me-4-nitrophenol, -37. 91 ‰ Reference CO2 Reference CO2 -33. 35 ‰ -15.17‰ Carbon Isotopic Measurement of Individual Organic in Secondary PM

  15. Continued method development of isotope measurements OC/EC in PM (i.e. using off-line extraction, followed by IRMS in the cold-finger dual inlet mode to replace coupling Pre-con system with GC-IRMS) for improving efficiency & detection limit without loosing data quality. Deliverables • Measured isotopic profiles of OC/EC for some source materials(i.e. bio- mass burning samples from fire-science laboratory, USDA). • Measurements of Fraserdale PM samples for understanding the impact of forest fire. • Method development of isotope measurements of individual organic compounds (e.g. n-Alkanes): - modifed the combustion interfaces in IRMSs (i.e. MAT252 and IsoPrime) - obtained the accuracy and precision of 0.5 ‰ in the linearity range of 1-50ng.

  16.  Publication L. Huang, W. Zhang, J. Brook, D. Ernst, A.Chivulescu, and G. Lu, [2004] Stable Isotope Measurements of Carbon Species (OC/EC) in Particulate Matter via Thermal Desorption/Combustion & GC-IRMS: A Tool for Source Identification & Apportionment, Ready for submitted to Atmos Envir (Special Issue), 2004. Satoshi Irei, Lin Huang, Fabrice Collin1, Wendy Zhang, Donald Hastie and Jochen Rudolph [2004] Flow reactor studies for stable carbon isotopic composition of secondary particulate organic matter generated by toluene/OH radical-initiated reactions, Ready for submission 2004.  Presentation Huang, L., W. Zhang, J. Brook, S. Sharma, D. Ernst, A.Chivulescu, and G. Lu, [2004] Carbon Stable Isotope Measurements of OC/EC in Airborne Particulate Matter via Thermal Desorption/Combustion & GC-IRMS: A tool for Source Identification & Apportionment, presented at the 8th International Conf. of Carbonaceous Particles in the Atmosphere, Sept. 14-16, 2004, Vienna, Austria. Sangeeta Sharma, David Lavoué, Lin Huang, Desiree Toom-Sauntry, Ping Huang, Jeff Brook, Doug Worthy [2004] Contribution of Forest Fires to the Carbonaceous Aerosols in the Canadian Boreal Region, presented at the 8th International Conference of Carbonaceous Particles in the Atmosphere, Sept. 14-16, 2004, Vienna, Austria. Satoshi Irei, Lin Huang, Fabrice Collin, Wendy Zhang, Donald Hastie D.; R. Koppmann, and J. Rudolph [2004] Laboratory studies of the stable carbon isotope ratio of particulate matter formed by the gas-phase oxidation of toluene, presented at EGU (European Geophysical Union) Meeting, April, 2004 (EGU04-A-02630). Satoshi Irei, Lin Huang, Fabrice Collin, Wendy Zhang, Donald Hastie D., and J. Rudolph[2004] Flow Reactor Studies for Stable Carbon Isotopic Composition of Secondary Particulate Organic Matter Generated by Toluene/OH Radical-Initiated Reactions, presented at 16th International Conference on Nucleation and Atmospheric Aerosols (ICNAA), Jul. 26-30, 2004, Kyoto, Japan. Deliverables

  17. Next Steps(work should be done ) • Continuing modification of the methodology(i.e. OC/EC minimizing OC/EC cross-impact & the impact of carbonate carbon)to obtain more representative isotope data for OC/EC. • Isotopic measurements ofindividual organic compounds in SOA from toluene/OH reaction (e.g. oxygenated organic • compounds, which are major species in the products) to develop a tool • for partitioning the contribution of SOA in ambient PM. • Isotopic measurements ofmore source materials (including natural and anthropogenic emissions) both for OC/EC and individual compounds. • Isotopic measurements of PM from background to understanding the distribution of sources on regional or global scales. Challenges ? lack of . . . .

  18. Thanks !

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