AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
PAH Distribution with Particle Size by Hi-Volume Impactor: Positive Artifact Correction
JAN BENDL, Jan Hovorka, Jan Topinka, Charles University in Prague
Abstract Number: 238 Working Group: Instrumentation and Methods
Abstract Comprehensive characterization of winter urban aerosol, conducted in two industrial cities in the Czech Republic – Ostrava (26 days) and Mladá Boleslav (14 days) during smog and non-smog periods, also included polycyclic aromatic hydrocarbons - PAH distributions with aerosol particle size. Size segregated aerosol samples were then used for toxicology and genotoxicology studies. Since those studies claim rather high aerosol masses, high-volume cascade impactor sampler - BGI 900 was employed. The sampler uses polyurethane foam substrates – PUF, which also retain gaseous PAH, i.e. exhibit positive sampling artifact – PSA. To evaluate the PSA, additional PUF target was placed beneath the back-up ultrafilter. Significant amounts of phenanthrene, anthracene, fluoranthene, pyrene and benzo(a)anthracene were captured in the PUF targets after 24 hour air sampling. The extent of the captured gaseous PAHs positively correlated with their individual vapor pressures (ranging from 10^4 to 10^-1 Pa). Other measured PAHs (coronene, benzo(ghi)perylene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene and indeno(1,2,3-cd)pyrene) with vapor pressures from 10^-5 to 10^-10 Pa did not exhibit the PSA. The PSA also depends on ambient air temperature. The deduction for the captured gaseous volatile PAHs ranged from units to tens of percent of measured particle size fractions of PAHs. The general model will be presented for calculating ambient air temperature-dependent ratio between solid and gaseous fractions for individual PAH captured on the PUF substrates in Hi-Vol BGI 900.
This work was supported by the project CENATOX under grant GAČR P503/12/G147.