Carbonaceous-Species Methods Comparison Study: Interlaboratory round-robin interpretation of results. Final report, 12 Jun 89-12 Dec 90

Technical Report · Thu Nov 01 00:00:00 EST 1990

OSTI ID:5826073

Shah, J J; Rau, J A

Total carbon (TC) and its components, organic carbon (OC) and elemental carbon (EC), are major constituents of source and ambient particulate material. At least twelve laboratories measure these species. TC can be measured within about 5% of the group average. However, OC and EC measurements traditionally show large inter-laboratory differences. To gain a better understanding of these differences, the results of the round robin laboratory inter-comparison part of 1986 Carbonaceous Species Methods Comparison Study (CSMCS), sponsored by the California Air Resources Board (ARB) and others, were examined. A set of 20 samples, which included four (4) ambient samples in triplicate and seven (7) source samples, was provided to the 12 participant laboratories. For the four ambient samples, the average coefficient of variation (CV=standard deviation/average x 100) across laboratories for TC, OC, and EC, were 7%, 6-9%, and 28-31%, respectively. The reported OC and EC differences among laboratories result from: (1) variations in the maximum temperatures that define the upper limit of OC vaporization and EC oxidation; (2) methods used to correct for OC to EC pyrolysis; (3) the analysis oven gaseous atmospheres used during different parts of the analysis; and (4) the analysis conditions specified by the analysis protocol and conditions actually achieved in the analysis.

• Research Organization: California State Air Resources Board, Sacramento, CA (United States). Research Div.
• OSTI ID: 5826073
• Report Number(s): PB-92-123827/XAB; ARB-R-91/469; CNN: ARB-A832-154
• Resource Relation: Other Information: See also PB89-191175 and PB89-232805. Sponsored by G2 Environmental, Inc., Portland, OR
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CARBON
CHEMICAL ANALYSIS
PARTICULATES
AIR POLLUTION
ECOLOGICAL CONCENTRATION
INTERLABORATORY COMPARISONS
POLLUTION SOURCES
PYROLYSIS
CHEMICAL REACTIONS
DECOMPOSITION
ELEMENTS
NONMETALS
PARTICLES
POLLUTION
THERMOCHEMICAL PROCESSES
540120* - Environment
Atmospheric- Chemicals Monitoring & Transport- (1990-)