Design and evaluation of a novel diffusion separator for measuring gas/particle distributions of semivolatile organic compounds

Polychlorinated biphenyls associated with fine particles (PM2.5) in the urban environment of chile: Concentration levels, and sampling volatilization losses

“…These SOCs may also volatilize from the collected particles during high‐volume sampling in a rate depending on the pressure gradient that exists through the filter, the air temperature and its accidental fluctuations, the accidental fluctuations of the gas‐phase concentrations of SOCs (more clean air may cause higher volatilization since the gas/particle partitioning equilibrium is shifted), and the intrinsic volatility of the compounds [8,33]. Moreover, the use of a diffusion denuder upstream of the filter decreases the concentrations of gas‐phase SOCs in the air that sequentially pass through the filter, and potentially greater volatilization losses may be caused than would occur without the denuder [10,33].…”

“…The average volatilization losses ranged between 54% (PCB 199) and 97% (PCBs 8ϩ5, 11,18), which are in the same range with those reported for n-alkanes (C 21 -C 30 ) and polynuclear aromatic hydrocarbons in a similar study [9]. These SOCs may also volatilize from the collected particles during high-volume sampling in a rate depending on the pressure gradient that exists through the filter, the air temperature and its accidental fluctuations, the accidental fluctuations of the gas-phase concentrations of SOCs (more clean air may cause higher volatilization since the gas/particle partitioning equilibrium is shifted), and the intrinsic volatility of the compounds [8,33]. Moreover, the use of a diffusion denuder upstream of the filter decreases the concentrations of gas-phase SOCs in the air that sequentially pass through the filter, and potentially M. Mandalakis and E.G.…”

An evaluation of measurement methods for organic, elemental and black carbon in ambient air monitoring sites

“…In practice the total carbon (TC = EC+OC) on filter samples is relatively well defined and can be measured by the thermal volatilisation of carbonaceous material combined with quantitative detection of the carbon produced, for example using a methanator and a flame ionisation detector. There is a separable issue of whether the material collected on filters is representative of carbonaceous material in the ambient atmosphere, as it is well known that semi-volatile organic compounds, for example, can lead to significant variations in collected material depending on the collection conditions (eg Turpin et al, 1993;Eatough et al, 1993). The majority of the methods described here are based on filter samples.…”

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

“…Recently a diffusion denuder coated with a nonpolar gas chromatographic stationary phase has been used for direct determination of gas-phase semi-volatile organics Hites, 1992, 1994). Turpin, et al (1993) recently tested a novel design for a diffusion separator that allows direct artifact-free determination of the gas phase of an airstream, but it has not yet been used for ambient sampling.…”