title: A Critical Evaluation of Interlaboratory Data on Total, Elemental, and Isotopic Carbon in the Carbonaceous Particle Reference Material, NIST SRM 1649a.
abstract: Because of increased interest in the marine and atmospheric sciences in elemental carbon (EC), or black carbon (BC) or soot carbon (SC), and because of the difficulties in analyzing or even defining this pervasive component of particulate carbon, it has become quite important to have appropriate reference materials for intercomparison and quality control. The NIST "urban dust" Standard Reference Material(®) SRM 1649a is useful in this respect, in part because it comprises a considerable array of inorganic and organic species, and because it exhibits a large degree of ((14)C) isotopic heterogeneity, with biomass carbon source contributions ranging from about 2 % (essentially fossil aliphatic fraction) to about 32 % (polar fraction). A primary purpose of this report is to provide documentation for the new isotopic and chemical particulate carbon data for the most recent (31 Jan. 2001) SRM 1649a Certificate of Analysis. Supporting this is a critical review of underlying international intercomparison data and methodologies, provided by 18 teams of analytical experts from 11 institutions. Key results of the intercomparison are: (1) a new, Certified Value for total carbon (TC) in SRM 1649a; (2) (14)C Reference Values for total carbon and a number of organic species, including for the first time 8 individual PAHs; and (3) elemental carbon (EC) Information Values derived from 13 analytical methods applied to this component. Results for elemental carbon, which comprised a special focus of the intercomparison, were quite diverse, reflecting the confounding of methodological-matrix artifacts, and methods that tended to probe more or less refractory regions of this universal, but ill-defined product of incomplete combustion. Availability of both chemical and (14)C speciation data for SRM 1649a holds great promise for improved analytical insight through comparative analysis (e.g., fossil/biomass partition in EC compared to PAH), and through application of the principle of isotopic mass balance.
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, USA (NIST).
authors.forename: L A
authors.initials: LA
authors.lastname: Currie
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, USA (NIST).
authors.forename: B A
authors.initials: BA
authors.lastname: Benner
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, USA (NIST).
authors.forename: J D
authors.initials: JD
authors.lastname: Kessler
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, USA (NIST).
authors.forename: D B
authors.initials: DB
authors.lastname: Klinedinst
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, USA (NIST).
authors.forename: G A
authors.initials: GA
authors.lastname: Klouda
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, USA (NIST).
authors.forename: J V
authors.initials: JV
authors.lastname: Marolf
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, USA (NIST).
authors.forename: J F
authors.initials: JF
authors.lastname: Slater
authors.affiliation: National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, USA (NIST).
authors.forename: S A
authors.initials: SA
authors.lastname: Wise
authors.affiliation: Centre des Science du Climat et de l'Environment, Ave de la Terasse, 91 198 Gif sur Yvette, Cedex, France (LSCE).
authors.forename: H
authors.initials: H
authors.lastname: Cachier
authors.affiliation: Sunset Laboratories, Inc. 2221 Yew St., Forest Grove, OR 97116, USA (SLI).
authors.forename: R
authors.initials: R
authors.lastname: Cary
authors.affiliation: Energy and Environmental Engineering Center, Desert Research Institute, Reno, NV 89512, USA (DRI).
authors.forename: J C
authors.initials: JC
authors.lastname: Chow
authors.affiliation: Energy and Environmental Engineering Center, Desert Research Institute, Reno, NV 89512, USA (DRI).
authors.forename: J
authors.initials: J
authors.lastname: Watson
authors.affiliation: Dept. of Earth System Science, University of California, Irvine, CA 92697, USA (UCI).
authors.forename: E R M
authors.initials: ER
authors.lastname: Druffel
authors.affiliation: Dept. of Earth System Science, University of California, Irvine, CA 92697, USA (UCI).
authors.forename: C A
authors.initials: CA
authors.lastname: Masiello
authors.affiliation: Dept. of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA (WHOI).
authors.forename: T I
authors.initials: TI
authors.lastname: Eglinton
authors.affiliation: Dept. of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA (WHOI).
authors.forename: A
authors.initials: A
authors.lastname: Pearson
authors.affiliation: Dept. of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA (WHOI).
authors.forename: C M
authors.initials: CM
authors.lastname: Reddy
authors.affiliation: Institute of Applied Environmental Research, Stockholm University, 10691 Stockholm, Sweden (SU).
authors.forename: Ö
authors.initials: Ö
authors.lastname: Gustafsson
authors.affiliation: Graduate School of Oceanography, Univ. Rhode Island, Narragansett, RI 02882, USA (URI).
authors.forename: J G
authors.initials: JG
authors.lastname: Quinn
authors.affiliation: Graduate School of Oceanography, Univ. Rhode Island, Narragansett, RI 02882, USA (URI).
authors.forename: P C
authors.initials: PC
authors.lastname: Hartmann
authors.affiliation: School of Oceanography, University of Washington, Seattle, WA 98195, USA (UW).
authors.forename: J I
authors.initials: JI
authors.lastname: Hedges
authors.affiliation: School of Oceanography, University of Washington, Seattle, WA 98195, USA (UW).
authors.forename: K M
authors.initials: KM
authors.lastname: Prentice
authors.affiliation: Atmospheric Aerosol Research, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA (LBNL).
authors.forename: T W
authors.initials: TW
authors.lastname: Kirchstetter
authors.affiliation: Atmospheric Aerosol Research, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA (LBNL).
authors.forename: T
authors.initials: T
authors.lastname: Novakow
authors.affiliation: Institute for Analytical Chemistry, Vienna University of Technology, Getreidemarkt 9/151, A-1060, Vienna, Austria (TUW).
authors.forename: H
authors.initials: H
authors.lastname: Puxbaum
authors.affiliation: Institute for Analytical Chemistry, Vienna University of Technology, Getreidemarkt 9/151, A-1060, Vienna, Austria (TUW).
authors.forename: H
authors.initials: H
authors.lastname: Schmid
keywords: 14C speciation; SRM 1649a; elemental carbon; fossil and biomass carbon; international intercomparison; total carbon certified value