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Carbon Isotopic Compositions of PM: Constraints on their Emission Sources and Formation Process For AQRB Branch Mid-Term Review (Oct. 25-27, 2004) Environment.

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Presentation on theme: "Carbon Isotopic Compositions of PM: Constraints on their Emission Sources and Formation Process For AQRB Branch Mid-Term Review (Oct. 25-27, 2004) Environment."— Presentation transcript:

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

2 Photochemical Oxidation of OCs  * R S Observation: R ob SOM Why measuring Isotopic Composition of PM Sources  13 C source i = (  13 C ff i  F ff ) + (  13 C bio i  F bio ) + (  13 C fire i  F fire ) + (  13 C bg i  F bg ) … Anthropogenic Plants  13 C = [(R sam /R Std ) -1]*10 3, R = 13 C/ 12 C

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 (AQRB) L. Huang, W. Zhang, A. Chivulescu, D. Ernst (AQRB) (York U.) S. Irei (York U.) Collaborators (AQRB) J. Brook, S. Sharma (AQRB) (Desert Research Institute, USA) Dr. Hans Moosmüller (Desert Research Institute, USA)

4 Experimental Method

5 550°C 870°C 850°C 100 % He 10 % O 2 + 90% He -20.72 ± 0.26 ‰ -25.34 ± 0.43 ‰ -26.04 ± 0.36 ‰ Laser separation of OC from EC Thermogram of OC/EC in Forest Sample 100ppm →1  g/per punch More than 90% samples lie in the range of 1 – 40  g/ per punch

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

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

8 Analytic precision : 0.3‰ Isotopic Compositions of Background Air

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

10 550°C 870°C 850°C 100 % He 10 % O 2 + 90% He - 32.90 ‰ (OC) - 32.91 ‰ (OC + CC) - 32.51 ‰ (EC) Laser separation of OC from EC 150°C 300°C 450°C 550°C 870°C 500°C 700°C 850°C OC1 OC2 OC3 OC4 OC+CC EC1 EC2 EC3 O2 + HeHe Secondary Organic Aerosols (Toluene reaction with OH - )

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

12 Method Development (Isotope Measurements of n-Alkanes)  Oxygen level  Accuracy: ~ 0.5 ‰ precision: ~ 0.5 ‰ precision: ~ 0.5 ‰ linearity: 1– 50 ng linearity: 1– 50 ng  Temp. of combustion  Temp. of combustion Ave. Std: ~ 0.5 ‰

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

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

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

16 Deliverables  Publication L. Huang, W. Zhang, J. Brook, D. Ernst, A.Chivulescu, and G. Lu,2004 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 Rudolph2004 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 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 Worthy2004 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. Rudolph2004] 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 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.

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

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