AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
The USEPA Coarse PM Pilot Speciation Study
HILARY MINOR, Jay Turner, Steven Brown, Paul Roberts, Joann Rice, Sonoma Technology, Inc.
Abstract Number: 599 Working Group: Instrumentation and Methods
Abstract The U.S. Environmental Protection Agency is continuing to explore the development of a speciation monitoring program for ambient coarse particulate matter (PM$_c) with multiple objectives, including the collection of data for health studies and source apportionment. Limited PM$_c speciation monitoring has been conducted in the past, and most such monitoring has mimicked the conventional PM$_(2.5) speciation network field sampling and analytical techniques. These PM$_(2.5) measurement techniques may not be optimal for PM$_c monitoring. Therefore, a pilot study was conducted from May 2010 to May 2011 at two sites to inform the development of PM$_c sampling and analysis protocols. 24-hour integrated samples were collected nominally every third day at the 43$^(rd) Street site in Phoenix (PHX) and the 13%^(th) Street & Tudor Avenue site in East St. Louis (ESL). The measurement platform included: four Thermo 2025 series sequential samplers at each site – a PM$_(2.5) FRM, a PM$_(10c) FRM and two dichotomous samplers (dichots); a MOUDI cascade impactor; and a Thermo 1405DF FDMS TEOM. Filter sandwiches of either Nylon-behind-Teflon or quartz-behind-quartz were used in the FRM and dichot samplers with routine analysis for gravimetric mass, elements by XRF, ions by IC, and OC/EC by TOR.
This poster will summarize key findings, including comparisons between the dichots and FRM by difference for gravimetric mass and individual species, dichot collocated precision, and mass balance closure. Results will also be presented for additional analyses, including ICP-MS, carbonate, organic speciation, and biological markers. In particular, the ICP-MS data are used to assess self absorption-induced biases in the XRF measurement of light elements. Finally, preliminary results will be presented for a follow-up study conducted in spring 2012 at Research Triangle Park evaluating changes that were made to the dichot by Thermo to obtain FEM designation.