Development of Research Strategies
for the Sampling and Analysis of
Organic and Elemental Carbon Fractions
in Atmospheric Aerosols
Questions & Sub-questions and Topic
- Robert Cary, President, Sunset Laboratory
- Lloyd Currie, Emeritus Fellow, National Institute
of Standards and Technology
- Judith Chow, Research Professor, Environmental
Analysis Facility, Desert Research Institute
- Hélène Cachier, France (invited)
- Joellen Lewtas, Senior Research Scientist,
US EPA/Office of Research & Dev’t/Nat’l Exposure
- Kirk Fuller, Research Scientist, National Space
Science and Technology Center, Univ. of Alabama
- Hans Hansson, Air Pollution Laboratory, Institute
of Applied Environmental Research and Department of Meteorology,
Stockholm University, Sweden
- Hans Moosmuller, Research Professor, Desert
Questions to be answered are:
1. What is elemental carbon and how do definitions differ
for different applications? What are the OC and EC properties
that are of importance to human health, visibility, climate, and
source attribution? To what extent can a single analytical method
or protocol meet these different needs?
Topic Leader: Robert Cary, President, Sunset Laboratory
2. What options exist for fundamental and traceable OC
and EC standards? What standards have been used in the
past? How well do these represent properties of user communities?
What other standards might be added? How can these be created,
maintained, and disseminated?
Topic Leader: Lloyd Currie, Emeritus Fellow, National
Institute of Standards and Technology
3. How does the sample affect the measurement of different
carbon fractions? How do properties of particles on a filter differ
from those in ambient air? How do different compounds
react with heat and among themselves to create pyrolized carbon?
How do different filter loadings affect optical measures of pyrolysis?
Under what conditions might other carbon-containing components
(e.g., carbonates) be detected as OC or EC? What additional information
should be reported with OC and EC values to evaluate the precision
and validity of an OC/EC split?
Judith Chow, Research Professor, Environmental Analysis
Facility, Desert Research Institute
4. What are the important parameters that need to be
defined for a carbonaceous aerosol analysis and how should these
be documented for different analysis protocols? How do
temperature plateaus, analysis times, combustion atmospheres,
heating rates, and optical pyrolysis monitoring affect the definition
of carbon fractions? What differences in analysis protocols should
be reported with OC and EC concentrations?
LSCE/CFR, laboratoire mixte CEA-CNRS, France
5. What specific compounds are likely to evolve during
different temperature fractions of thermal evolution methods used
to analyze carbonaceous aerosols? To what extent do similar
compounds evaporate within definable temperature groupings? How
well do current temperature-defined fractions defined useful groupings?
How might temperature fractions or the detection of thermally-evolved
products be optimized for applications such as source attribution?
Joellen Lewtas, Senior Research Scientist, US EPA/Office
of Research & Dev’t/Nat’l Exposure Research
6. How does carbonaceous particle composition, shape,
and size affect optical properties in the air and when sampled
on a filter? How might optical properties of particles
in the air differ from those collected on a filter? How might
filter transmittance and reflectance change during heating as
particle morphology and composition change? Why might optical
transmission and reflectance give different pyrolysis corrections?
Kirk Fuller, Research Scientist, National Space Science
and Technology Center, Univ. of Alabama
7. How might current analysis methods be enhanced or
combined to obtain more information about the nature of OC, EC,
and other carbon fractions in filter samples? What can
be done with existing analysis methods and samples? What might
be provided by collocated measurements? What hardware and software
changes would permit more of the commonly applied protocols to
be applied with the same analytical instruments?
Hans Hansson, Air Pollution Laboratory, Institute of
Applied Environmental Research and Department of Meteorology,
Stockholm University, Sweden
8. What new and innovative sampling, analytical, and interpretive
techniques are needed to determine the properties and sources
of carbonaceous aerosol in the atmosphere? What is the
role of in situ and laboratory analysis now and in the future?
How can multiple measurements in space and time assist in the
interpretation of and validation of OC/EC fractions? How might
new technologies satisfy the needs of multiple users? How might
they better quantify OC and EC sources for emissions reduction
Hans Moosmuller, Research Professor, Desert Research
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