Aerosol collection by cascade impaction and filtration: Influence of different sampling systems on the measured organic pollutant levels

Atmospheric Size Distribution of PAHs: Evidence of a High-Volume Sampling Artifact

“…During the current study, excellent agreement between the concentrations (ΣPAH) measured by TSP, PM10, and impactor samplers indicated relatively constant wind direction during the sampling periods and that the impactor collected comparable PAH content. Similar to our observations, several validation exercises have reported good agreement (within 20%) between conventional hi-vol samplers and the use of a hi-vol cascade impactor module unit for sampling periods ranging from 72 h to 1 week (27,28).…”

“…Adsorp tion−desorption reactions after sampling would be independent of our analysis since all filter samples (hi-vol and fritted) were treated equally during transportation in the field, as well as handling in the laboratory prior to PAH extraction. Moreover, where studies have shown comparable sampling efficiencies for the two methodologies ( , ), vaporization of the heavier PAHs (five- to six-ring) should not be an important factor ( , ). Although an increased sampling period may increase the elution of some PAHs, filters in the cascade impactor (fritted and hi-vol) are subject to the same sample volume.…”

Differences in particle size distributions of major organic pollutants in ambient aerosols in urban, rural, and seashore areas

“…Volatilization from collected material during sampling can be expected for the more volatile organic compounds such as the aliphatic hydrocarbons, the low molecular weight PAH, and carboxylic acids (10). The alternation of the aliphatic hydrocarbons is explained tentatively by assuming selective volatilization of the even n-alkanes compared to the uneven ones, as discussed in an earlier paper (9). However, it seems that desorption of the even aliphatic hydrocarbons could occur not only from collected material during sampling but also during transport of the aerosol in the atmosphere ("aerodynamic elution", 7).…”

“…We checked the consistency of the impactor results with samples taken by Hi-Vol filtration according to Dams and Heindryckx (14). In most cases, the individual pollutant concentrations for the impactor samples agreed within 20% with the Hi-Vol filtration results (9).…”

“…The performance of the slotted impactor used in this study was evaluated by Willeke (5). Previously, the possibility of losses by volatilization from collected particles during sampling was established for some organic compounds (6)(7)(8)(9). Cautreels and Van Cauwenberghe (10) reported quantitative data on the distribution of some pollutants between the gas phase and particulate matter for Hi-Vol filtration.…”