DIRECT DETERMINATION OF THE PHASE DISTRIBUTIONS OF SEMIVOLATILE POLYCYCLIC AROMATIC-HYDROCARBONS USING ANNULAR DENUDERS

An annular denuder-based sampler, here called the integrated organic v apor/particle sampler (IOVPS), has been developed for direct determina tion of both gaseous and particulate semi-volatile organic species. Th e IOVPS uses a cyclone inlet for removal of particles greater than 2.5 mu m (D-50) from the airstream, followed by two or three sandblasted glass annular denuders coated with ground particles of an adsorbent re sin. The denuders trap the gas-phase species of interest before the ai rstream passes through a filter and a backup denuder. Extracts of the denuders and filters are analyzed for the semi-volatile species of int erest. The IOVPS has been tested and validated for sampling semi-volat ile polycyclic aromatic hydrocarbons (PAH) in indoor laboratory room a ir and environmental tobacco smoke (ETS). Ground XAD-4 was the adsorbe nt for these initial studies. Gas- and particulate-phase concentration s of semi-volatile PAH are presented for these two environments. The n ew sampler provides the means for directly determining phase distribut ions of PAH and other classes of semi-volatile organic species, rather than by difference or by techniques that are subject to large positiv e and negative artifacts.