title: Characterizing PUF disk passive air samplers for alkyl-substituted PAHs: Measured and modelled PUF-AIR partition coefficients with COSMO-RS.
abstract: Isomers of alkyl-substituted polycyclic aromatic hydrocarbons (PAHs) and dibenzothiophenes are modelled with COSMO-RS theory to determine the effectiveness and accuracy of this approach for estimation of isomer-specific partition coefficients between air and polyurethane foam (PUF), i.e., KPUF-AIR. Isomer-specific equilibrium partitioning coefficients for a series of 23 unsubstituted and isomeric alkyl-substituted PAHs and dibenzothiophenes were measured at 22 °C. This data was used to determine the accuracy of estimated values using COSMO-RS, which is isomer specific, and the Global Atmospheric Passive Sampling (GAPS) template approach, which treats all alkyl-substitutions as a single species of a given side-chain carbon number. A recently developed oligomer-based model for PUF was employed, which consisted of a 1:1 condensed pair of 2,4-toluene-diisocyanide and glycerol. The COSMO-RS approach resulted in a significant reduction in the RMS error associated with simple PAHs and dibenzothiophene compared with the GAPS template approach. When used with alkylated PAHs and dibenzothiophenes grouped into carbon-number categories, the GAPS template approach gave lower RMS error (0.72) compared to the COSMO-RS result (0.87) when the latter estimates were averaged within the carbon-number-based categories. When the isomer-specific experimental results were used, the COSMO-RS approach resulted in a 21% reduction in RMS error with respect to the GAPS template approach, with a 0.57 RMS error for all alkylated PAHs and dibenzothiophenes studied. The results demonstrate that COSMO-RS theory is effective in generating isomer-specific PUF-air partition coefficients, supporting the application of PUF-based passive samplers for monitoring and research studies of polycyclic aromatic compounds (PACs) in air.
authors.affiliation: Chemical Properties Research Group, Department of Chemistry, Trent University, Peterborough, ON K9J 7B8, Canada. Electronic address: mparnis@trentu.ca.
authors.forename: J Mark
authors.initials: JM
authors.lastname: Parnis
authors.affiliation: Air Quality Processes Research Section, Environment Canada, 4905 Dufferin St., Toronto, ON M3H 5T4, Canada.
authors.forename: Anita
authors.initials: A
authors.lastname: Eng
authors.affiliation: Chemical Properties Research Group, Department of Chemistry, Trent University, Peterborough, ON K9J 7B8, Canada.
authors.forename: Donald
authors.initials: D
authors.lastname: Mackay
authors.affiliation: Air Quality Processes Research Section, Environment Canada, 4905 Dufferin St., Toronto, ON M3H 5T4, Canada.
authors.forename: Tom
authors.initials: T
authors.lastname: Harner
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D008962:Models, Theoretical; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D011140:Polyurethanes
chemical_list: D000393:Air Pollutants; D011084:Polycyclic Aromatic Hydrocarbons; D011140:Polyurethanes; C028279:polyurethane foam
keywords: COSMO-RS; Environmental monitoring; PAH isomers; PUF; Partitioning; Passive sampling; Polyurethane foam disk