Development of a Reference Standard for Particulate Matter Mass in Ambient Air

Abstract

Particulate matter (PM) in ambient air is composed of many chemical species of varying vapor pressures. A direct mass measurement of PM mass on lters is the basis of regulatory PM reference methods. The loss of semi-volatile PM mass collected on lters and lter sampling artifacts can produce nonquanti able biases in reference method measurements depending on the thermodynamic history of the lter; therefore, a reference method cannot be considered a scienti c reference standard. A new technique is introduced which has the potential to overcome the dif culties inherent in PM mass measurement and holds the promise of the measurement of PM mass as it exists in ambient air at ambient temperature. While comprehensive laboratory and eld studies of the instrument and its components are needed to fully characterize the system, preliminary data have been obtained to provide a basic proof of concept for the technique.

Biomass burning impact on PM<sub> 2.5</sub> over the southeastern US during 2007: integrating chemically speciated FRM filter measurements, MODIS fire counts and PMF analysis

“…For this study, archived FRM filters that had been in storage (in the dark at a T <−20 • C) for roughly a year were acquired from state regulatory agencies in Georgia (GA Department of Natural Resources), South Carolina (SC Department of Health and Environmental Control) and Alabama (AL Department of Environmental Management and the Jefferson Co. Department of Health). The FRM method for collecting ambient fine particles onto Whatman 47 mm Teflon filter substrates involved 24-hour integrated sampling at a nominal flow rate of 16.7 L/min with PM 2.5 sharp cut cyclone size selector or PM 2.5 WINS impactor and with no gas-denuders (Patashnick et al, 2001). Fifteen sampling sites throughout the southeastern US were chosen within the EPA FRM monitoring network, on the basis of geographic location, site type (i.e.…”

Measurement of total PM2.5 mass (nonvolatile plus semivolatile) with the Filter Dynamic Measurement System tapered element oscillating microbalance monitor

“…R&P recently developed the differential TEOM monitor as a reference standard for particulate matter mass as described by Patashnick et al [2001], and subsequently developed the Filter Dynamics Measurement System (FDMS) [ Meyer et al , 2002], both of which attempt to correct for loss of semivolatile species from the TEOM filter by alternately making measurements with particle‐containing and particle‐free air passing through the filters on the tapered element oscillating microbalance of a TEOM monitor. In this study, the new FDMS monitor is being evaluated by comparison of measurements with a RAMS and a differential TEOM system similar to that described by Meyer et al [2002].…”

Development of a Sample Equilibration System for the TEOM Continuous PM Monitor

“…[4][5][6][7] Others have taken advantage of its exacting mass measurement principle to study alternate configurations of the TEOM mass sensor that optimize the retention of semi-volatile compounds. 8,9 In regions where the presence of light molecular weight semi-volatile particles represents an appreciable fraction of the PM mass, it is desirable to maintain as low an operating temperature as practical while also removing unwanted particle-bound water. The primary goal is to introduce an add-on component for the TEOM monitor that can help meet this condition and thus provide a 24-hr integrated PM mass concentration measurement more comparable to that of the FRM.…”