Collection and characterization of a bulk PM2.5 air particulate matter material for use in reference materials

A contemporary PM2.5 (particulate matter smaller than 2.5 mu m aerodynamic diameter) aerosol material from an urban site has been collected for the pr oduction of a new standard reference material that will be made available f or the development of new PM2.5 air quality standards. Air particulate matt er corresponding to the PM2.5 fraction was collected at an established Envi ronmental Protection Agency monitoring site in Baltimore, Maryland. The air -sampling system that has been constructed for this collection separates fi ne particles with a cyclone separator and deposits them onto an array of Te flon membrane filters. The fine air particulate material is removed by ultr asonication or by mechanical means and collected for further preparation of standards. The composition of the collected PM2.5 aerosol, as well as the composition of the deposited PM2.5 aerosol, are determined by instrumental nuclear activation analysis and other techniques.