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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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slide1
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)

slide2
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

slide3
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)

slide5
-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

slide6
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

slide7
Isotope compositions in Different Source Profiles and Ambient Air

(Pacific 2001 Campaigns)

slide8
Isotopic Compositions of Background Air

Analytic precision : 0.3‰

slide9
Carbon Isotopic Compositions of PM (OC/EC)

from Bio-mass Burning and Their Source Materials

Mean Std: < 0.2 ‰

C4

C3

slide10
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-)

slide11
PM 2.5

Analytic precision :<0.3‰

Carbon Isotopic Compositions in PM (Fraserdale, May - Aug. 2003)

TSP

TSP

Analytic precision : <0.3‰

slide12
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

slide13
Isotope Measurements of Individual Compounds (e.g. n-Alaknes)

Accuracy & precision of the method: ~ 0.5‰

slide14
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

deliverables
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.

deliverables1
 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

next steps work should be done

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 . . . .

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