| Abstract
| - A detailed comparison of two inherently different ambientair samplers has been conducted to fully characterizeand compare their performance in sampling and measuringthe partitioning of a suite of 29 semivolatile organiccompounds (SVOCs). A high volume air sampler (hi-vol)utilizing polyurethane foam (PUF) adsorbent for vapor-phasetrapping and an annular diffusion denuder sampler wereoperated concurrently. Sampling artifacts were observedand can be related to the physicochemical properties of theanalytes and the designs of the samplers. The resultssuggest that high volume air samplers equipped with PUFare unsuitable for measuring those organochlorinecompounds and 2- and 3-ring PAHs which have subcooledliquid vapor pressures (p°L) greater than ca. 0.2 Pa (log[p°L] = −0.7), owing to their breakthrough on PUF samplingmedia at relatively low sample volumes (170 m3) andambient temperatures typical of temperate regions (mean= 11 °C, max = 18 °C). Theoretical calculations ofbreakthrough volumes for SVOCs on PUF are presentedand in most cases these successfully predict observedbehavior. The denuder sampler is more efficient at measuringthe relatively volatile SVOCs. For total SVOC measurementsthe hi-vol and denuder were in good agreement forthose compounds which were efficiently sampled, andthe denuder yielded total SVOC concentrations which differedby a mean factor of 1.2 relative to those obtained withthe hi-vol sampler. The hi-vol sampler provides goodagreement with the Junge-Pankow model for partitioningof the relatively less volatile PAHs (log[p°L] < −3), though thefraction of the PCBs in the particle-phase is underestimated.The results from the diffusion denuder indicate that forthe more volatile SVOCs (log[p°L] > −3), particulate loadingsare overestimated with respect to the Junge-Pankowmodel, and for less volatile SVOCs, particulate loadingstend to be underestimated. An important observation is thatthe results from the denuder indicate that PCBs may beadsorbed on atmospheric particulate matter to a similardegree as PAHs.
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