Use of
a Versatile High Efficiency Multiparallel Denuder
for the Sampling of PAHs in Ambient Air: Gas and Particle Phase Concentrations,
Particle Size Distribution and Artifact Formation
posted on 2015-12-17, 00:12authored byJuana
Maria Delgado-Saborit, Christopher Stark, Roy M. Harrison
The
design and performance of a multiparallel plate denuder able
to operate at low and high-flow (3–30 L/min) for the collection
of polycyclic aromatic hydrocarbon (PAH) vapor is described. The denuder,
in combination with a micro orifice uniform deposit impactor (MOUDI)
was used to assess processes of artifact formation in MOUDIs used
with and without an upstream denuder. Duplicate sampling trains with
an upstream denuder showed good repeatability of the measured gas
and particle-phase concentrations and low breakthrough in the denuder
(3.5–15%). The PAH size distributions within undenuded and
denuded MOUDIs were studied. Use of the denuder altered the measured
size distribution of PAHs toward smaller sizes, but both denuded and
undenuded systems are subject to sampling artifacts.