AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Evaluation of a Thermophoretic Nanoparticle Sampler
TRACI LERSCH, Kristin Bunker, David Leith, John Volckens, Gary Casuccio, RJ Lee Group, Inc.
Abstract Number: 478 Working Group: Aerosol Exposure
Abstract A portable thermophoretic nanoparticle sampler has been developed that deposits airborne ultra-fine particles onto an electron microscopy (EM) grid. The particles on the grid can be subsequently measured and speciated using EM techniques to provide an assessment of exposures. Particle collection efficiencies associated with the sampler were initially evaluated in laboratory experiments that involved simultaneous collection with a scanning mobility particle spectrometer (SMPS) using a salt aerosol (phosphate-buffered saline). These experiments, along with theory of thermophoretic velocity, were used to establish the collection efficiency of the sampler. From these studies, a transfer function was developed that relates the size distributions and number concentrations of the collected particles to the aerosol.
In an effort to evaluate the ability of the thermophoretic sampler to provide an accurate measure of airborne nanoparticle concentrations, additional chamber studies were performed using different materials. Also, the sampler was employed in field studies representative of real world conditions. Data are provided illustrating the comparison of thermal precipitator sampler results to SMPS data with a focus on the validity of the transfer function. Data are also provided from field studies illustrating the potential of the sampler for use in exposure assessment.