A Critical Evaluation of Interlaboratory Data on Total, Elemental, and Isotopic Carbon in the Carbonaceous Particle Reference Material, NIST SRM 1649a

• Published in: Journal of research of the National Institute of Standards and Technology Vol. 107; no. 3; pp. 279 - 298
• Main Authors: Currie, L A, Benner, Jr, B A, Kessler, J D, Klinedinst, D B, Klouda, G A, Marolf, J V, Slater, J F, Wise, S A, Cachier, H, Cary, R, Chow, J C, Watson, J, Druffel, E R M, Masiello, C A, Eglinton, T I, Pearson, A, Reddy, C M, Gustafsson, Ö, Quinn, J G, Hartmann, P C, Hedges, J I, Prentice, K M, Kirchstetter, T W, Novakow, T, Puxbaum, H, Schmid, H
• Format: Journal Article
• Language: English
• Published: United States National Institute of Standards and Technology 01.05.2002; Superintendent of Documents; National Institute of Standards (NIST); [Gaithersburg, MD] : U.S. Dept. of Commerce, National Institute of Standards and Technology
• Subjects: 14C speciation; Analysis; Atmospheric research; Carbon; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; elemental carbon; fossil and biomass carbon; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Instruments & Instrumentation; international intercomparison; Marine sciences; OTHER INSTRUMENTATION; Physics; SRM 1649a; total carbon certified value; United States; SRM 1649a; total carbon certified value; 14C speciation; elemental carbon; international intercomparison; fossil and biomass carbon
• ISSN: 1044-677X; 2165-7254
• DOI: 10.6028/jres.107.022

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.