Equilibrium vapour concentrations of some polycyclic aromatic hydrocarbons, As4O6 and SeO2 and the collection efficiencies of these air pollutants

Direct determination of the phase distributions of semi-volatile polycyclic aromatic hydrocarbons using annular denuders

“…Phase distributions of semi-volatile species depend not only on vapor pressures (Pupp, et al, 1974) and temperature (Keller and Bidleman, 1984;Cotham and Bidleman, 1992), since vapor pressure is a function of temperature, but also on sampling conditions such as the face velocity (Della Fiorentina, et al, 1975;McDow and Huntzicker, 1990) and sampling duration (Della Fiorentina, et al, 1975). This is clear from measurements of organic carbon collected on backto-back filters (Appel, et al, 1989;McDow and Huntzicker, 1990) and aliphatic infrared C-H absorbance indices for filter-collected ambient organics (Della Fiorentina, et al, 1975).…”

“…Very little benz(a)anthracene and chrysene were found in the gas phase for ETS. Generally, the particulate fraction increased as molecular weight increased and vapor pressure decreased (Pupp, et al, 1974;Sonnefeld, et al, 1983). No detectable amounts of PAH were found on the second filters or the post-filter denuders.…”

“…Gas-phase concentrations have been determined from the material retained by the adsorbents. Since such sorbent beds follow filters, desorption of semi-volatile compounds from the particles on the filters, ie., negative particulatephase artifacts, (Pupp, et al, 1974;Della Fiorentina, et al, 1975;Van Vaeck, et al, 1984;Miguel and De Andrade, 1986) or adsorption of gases by the filter materials, i.e., positive particulate-phase artifacts, (Stevens, et al, 1980;Appel, et al, 1989;McDow and Huntzicker, 1990) can lead to incorrect measurements of gas-and particulate-phase concentrations. Considerable experimental (Della Fiorentina, et al, 1975;McDow and Huntzicker, 1990;Ligocki and Pankow, 1989;Storey and Pankow, 1992;Cotham and Bidleman, 1992) and theoretical effort (Junge, 1977;Pankow, 1987Pankow, , 1992 has been expended to understand and correct for these vaporization and condensation effects.…”

Particulate Emission Factors for Small Wood and Coal Stoves

“…Other studies 5 have shown that many of the chemical constituents of interest have large enough vapor pressures to cause them to exist largely in the vapor state in the atmosphere. The primary objective of the current series of measurements is to approximate more closely the atmosphere with regard to filterable material.…”

Sampling and analysis of trace-organic constituents in ambient and workplace air at coal-conversion facilities

“…However, Pupp et al (1974) have warned that some PARs .have sufficient vapor pressures that losses may occur from the particulates th~t are trapped on the ·filter.…”