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GUIDELINES FOR THE APPLICATION OF SEM/EDX ANALYTICAL TECHNIQUES FOR FINE AND COARSE PM SAMPLES
Citation:
Willis, R. D. AND T L. Conner. GUIDELINES FOR THE APPLICATION OF SEM/EDX ANALYTICAL TECHNIQUES FOR FINE AND COARSE PM SAMPLES. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-02/070 (NTIS PB2004-100988), 2003.
Impact/Purpose:
The NERL SEM/EDX facility was established to provide a state-of-the-art resource for individual particle analysis. Specific goals of the laboratory are as follows: 1) Provide chemical, morphological, and size characterization of particles in support of ambient air characterization studies, source apportionment, exposure and health studies, and other particulate matter research.; 2) Develop analytical capabilities to support research objectives; 3) Communicate results to clients and the scientific community.
Description:
Scanning Electron Microscopy (SEM) coupled with Energy-Dispersive X-ray analysis (EDX) is a powerful tool in the characterization and source apportionment of environmental particulate matter (PM), providing size, chemistry, and morphology of particles as small as a few tenths of a micrometer. Such information can reveal information about emission sources which cannot be determined through bulk chemical analysis. Automated SEMs capable of routinely analyzing hundreds of particles per hour have dramatically increased the throughput of SEM/EDX, making it feasible to conduct statistically meaningful analyses of PM samples and to generate large data sets for source apportionment studies.
The National Exposure Research Laboratory (NERL) of the U.S. EPA has been developing and evaluating the use of SEM/EDX to characterize ambient and source-derived particles. The present document, which evolved over several years as a product of research carried out in support of the U.S. EPA/NERL SEM/EDX Laboratory, is intended to provide guidelines for researchers using SEM/EDX for aerosol characterization and source apportionment. Topics include laboratory procedures for sample handling, sample preparation, guidelines for successful manual and automated SEM/EDX analyses, data interpretation, issues relating to data quality and method validation and case studies highlighting the use of SEM/EDX in PM research.
The information in this document has been funded wholly by the United States Environmental Protection Agency under contract number 68D00206 to ManTech Environmental Technology, Inc. It has been subjected to the Agency's peer and administrative review and has been approved for publication as an EPA document.