Thermal-Optical-Transmittance Analysis for Organic, Elemental, Carbonate, Total Carbon, and OCX2 in PM2.5 by the EPA/NIOSH Method
Peterson, M. R., & Richards, M. H. (2002). Thermal-Optical-Transmittance Analysis for Organic, Elemental, Carbonate, Total Carbon, and OCX2 in PM2.5 by the EPA/NIOSH Method. In .
Research Triangle Institute (RTI) performs thermal-optical-transmittance (TOT) analyses for carbon species in PM2.5 collected on quartz fiber filters as part of several Federal and State ambient air monitoring programs and human exposure studies. U.S. National Institute for Occupational Safety and Health (NIOSH) Method 5040, an evolved gas TOT method, was chosen for measurement of organic carbon (OC), elemental carbon (EC), carbonate carbon (CC), total carbon (TC), and OCX2 (the most refractory component of OC) in PM2.5 samples collected in the U.S. Environmental Protection Agency's (EPA's) nationwide chemical speciation program. Primary instrumentation in RTI's OC/EC Laboratory includes three Sunset Laboratory Thermal/Optical Carbon Analyzers and a muffle furnace used to pre-clean quartz filters.
This presentation includes an overview of the EPA/NIOSH TOT analysis; observations on the challenges posed by using multiple instruments and multiple analysts for an analysis in which the analytes are defined by the conditions of the analysis; estimates of the precision of the EPA/NIOSH method; and a comparison of the conditions used for the EPA/NIOSH method with the conditions used for other thermal-optical analysis methods and how those differences affect measurement results.