title: Comparison of quartz and Teflon filters for simultaneous collection of size-separated ultrafine aerosol particles and gas-phase zero samples.
abstract: In this research, the two most common filter media, quartz and Teflon, were tested to obtain information about the possible adsorption of gas-phase compounds onto filters during long sample collection of atmospheric aerosols. Particles of nanometer-size for off-line chemical characterization were collected using a recently introduced differential mobility analyzer for size separation. Samples were collected at an urban site (Helsinki, SMEARIII station) during spring 2010. Sampling time was 4 to 10 days for particles 50, 40, or 30 nm in diameter. Sample air flow was 4 L/min. The sampling setup was arranged so that two samples were obtained for each sampling period almost simultaneously: one containing particles and adsorbed gas-phase compounds and one containing adsorbed gas-phase compounds only. Filters were extracted and analyzed for the presence of selected carboxylic acids, polyols, nitrogen-containing compounds, and aldehydes. The results showed that, in quartz filter samples, gas-phase adsorption may be responsible for as much as 100% of some compound masses. Whether quartz or Teflon, simultaneous collection of gas-phase zero samples is essential during the whole sampling period. The dependence of the adsorption of gas-phase compounds on vapor pressure and the effect of adsorption on the deposited aerosol layer are discussed.
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, Helsinki, Finland.
authors.forename: Jevgeni
authors.initials: J
authors.lastname: Parshintsev
authors.forename: Jose
authors.initials: J
authors.lastname: Ruiz-Jimenez
authors.forename: Tuukka
authors.initials: T
authors.lastname: Petäjä
authors.forename: Kari
authors.initials: K
authors.lastname: Hartonen
authors.forename: Markku
authors.initials: M
authors.lastname: Kulmala
authors.forename: Marja-Liisa
authors.initials: ML
authors.lastname: Riekkola
mesh_terms: D000336:Aerosols / Q000302:isolation & purification*; D004784:Environmental Monitoring / Q000379:methods*; D005374:Filtration; D010316:Particle Size; D011138:Polytetrafluoroethylene; D011791:Quartz
chemical_list: D000336:Aerosols; D011791:Quartz; D011138:Polytetrafluoroethylene