Measurements of the gas/particle distributions of atmospheric organic compounds

Ligocki, Mary P.; Pankow, James F.

doi:10.1021/es00178a009

Cited by 206 publications

(123 citation statements)

References 22 publications

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“…Procedures such as ® lter or impactor sampling, followed by solvent extraction and gas-chromatograph y-mass ( ) ( spectrometry GCMS Forstner et al ) 1997a, b , can suffer from artifacts due to adsorption r desorption of vapors during ( sampling Ligocki and Pankow, 1989; Mc-) Dow and Huntzicker 1990 and contamination due to handling and analytical procedures. With TDPBMS these problems are minimized because the time required to sample and analyze particles is -1 s and particles only brie¯y contact a surface during analysis.…”

Section: :1] 2 July] August 2000mentioning

confidence: 99%

Real-Time Chemical Analysis of Organic Aerosols Using a Thermal Desorption Particle Beam Mass Spectrometer

Tobias

Kooiman

Docherty

et al. 2000

Aerosol Science and Technology

135

155

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ABSTRACT. An instrument has been developed for real-time, quantitative chemical analys is of organic particles in laboratory environments. In this apparatus, ( ) which we call a Thermal Desorption Particle Beam Mass Spectrometer TDPBMS , particles are sampled into a differentially-pumped vacuum chamber, focused into a narrow, low-divergence particle beam us ing aerodynamic lenses, and then transported into a high-vacuum region where they impact on a heated surface, evaporate, and the vapor is mass analyzed in a quadrupole mass spectrometer.

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Section: :1] 2 July] August 2000mentioning

confidence: 99%

Real-Time Chemical Analysis of Organic Aerosols Using a Thermal Desorption Particle Beam Mass Spectrometer

Tobias

Kooiman

Docherty

et al. 2000

Aerosol Science and Technology

135

155

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“…To estimate CB ,0 we can use Aerosol Science and Technology 30:1 January 1999 Measurement of Absorption Artifact in an Impactor 25 gas-particle distribution ratios, f , which have been measured for PAHs in the atmosphere by a number of investigators (Yamasaki et al 1982;Pyysalo et al 1987;McVeety and Hites 1988;Ligocki and Pankow 1989). Measured values of f were determined from the literature as…”

Section: Criterion 1: Equilibrium Absorptionmentioning

confidence: 99%

“…A signi cant fraction of lower molecular weight PAHs have been reported to partition to the gas phase in the atmosphere (Yamasaki et al 1982;Pyysalo et al 1987;McVeety and Hites 1988;Tuominen et al 1988;Ligocki and Pankow 1989). These compounds are readily soluble in oils and may absorb from the gas phase into the oiled impaction substrates during atmospheric sampling.…”

Section: Introductionmentioning

confidence: 99%

Absorption of Semi-Volatile Compounds in Oiled Impaction Substrates: Measurement of Pyrene Absorption

Allen¹

1999

Aerosol Science and Technology

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ABSTRACT. Oiled impaction substrates have been used to prevent particle bounce during the collection of size-segregated aerosol samples, which have been analyzed for trace-level airborne organic compounds, including polycyclic aromatic hydrocarbons (PAHs). The use of the oiled impaction substrates, however, may introduce another sampling artifact-the absorption of semivolatile species from the gas phase which could arti cially increase the amount of PAHs attributed to the aerosol. In this article, laboratory measurements of the absorption of a particular PAH, pyrene, from the gas phase to impaction substrates of polytetra uoroethylene membranes impregnated with dibutyl phthalate are reported. Overall mass transfer coef cients are determined from the data. These results are used to calculate the absorption of gas phase PAHs during sampling of size-segregated atmospheric particles. Criteria are developed to determine if the absorption artifact is negligible. The rst criterion requires that the analyte be negligibly soluble in the oil; this criterion is met by none of the impaction oils reported in the literature. The second criterion is that species do not have time to reach an equilibrium distribution between the gas phase and impaction oil; this criterion is met for nonvolatile species, those with vapor pressures equal to or less than that of benzo[a]pyrene (3.5 3 10 6 Pa). We recommend that oiled impaction substrates be used only if the absorption artifact is expected to be negligible on the basis of these criteria.

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“…Volatilization of organic analytes from collected particles may be reduced by maintaining constant temperature conditions and a low pressure drop across the filter [7].…”

Section: Introductionmentioning

confidence: 99%

“…These are principally from sorption of gas phase analytes onto the filter or collected particles as well as from desorption of analytes from these particles. The adsorption of gas phase PAHs onto the filter medium can be significant and may be estimated from a second particle-free backup filter [7].…”

Section: Introductionmentioning

confidence: 99%

The use of multi-channel silicone rubber traps as denuders for polycyclic aromatic hydrocarbons

Forbes

Karg

Zimmermann

et al. 2012

Analytica Chimica Acta

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HIGHLIGHTS:o Two multi-channel silicone rubber traps separated by a quartz fibre filter are characterized as a miniature portable denuder o Gas and particle phase polycyclic aromatic hydrocarbons can be separately sampled and analysed o Calculated particle transmission efficiencies were 100 % for particles > 50 nm diameter o Experimental particle transmission efficiencies were 100 % for particles > 200 nm and decreased to < 60 % for particles < 20 nm diameter o Short sampling intervals are possible which provides high temporal resolution for air pollution studies Analytica Chimica Acta Novelty StatementTwo multi-channel silicone rubber traps separated by a quartz fibre filter are characterized as a miniature portable denuder, which allows for the separate sampling and analysis of gas and particle phase polycyclic aromatic hydrocarbons. Calculated particle transmission efficiencies were 100 % for particles > 50 nm diameter, whilst experimental particle transmission efficiencies were 100 % for particles > 200 nm and decreased to < 60 % for particles < 20 nm diameter. Short sampling intervals are possible which provides high temporal resolution for air pollution studies. , separated by a quartz fibre filter for particle phase collection. The denuder only requires a small portable personal sampling pump to provide sampling flow rates of ~0.5 L min -1 . Theoretical considerations indicated that the air flow through the denuder was expected to be laminar, and the linear velocity arising from longitudinal diffusion was found to be negligible. The calculated particle transmission efficiency through the denuder was found to be essentially 100 % for particles > 50 nm, whilst the experimental overall efficiency, as determined by CPC and SMPS measurements, was 92 ± 4 %. The size resolved transmission efficiency was < 60 % for particles below 20 nm and 100 % for particles larger than 200 nm. Losses could have been due to diffusion and electrostatic effects. Semi-volatile gaseous analytes are pre-concentrated in the silicone of the trap and may be thermally desorbed using a commercially available desorber, allowing for total transfer and detection of the collected analytes by GC-MS. This enhances detection limits and allows for lower sampling flow rates and shorter sampling times, which are advantageous for studies requiring high temporal resolution.

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Measurements of the gas/particle distributions of atmospheric organic compounds

Cited by 206 publications

References 22 publications

Real-Time Chemical Analysis of Organic Aerosols Using a Thermal Desorption Particle Beam Mass Spectrometer

Real-Time Chemical Analysis of Organic Aerosols Using a Thermal Desorption Particle Beam Mass Spectrometer

Absorption of Semi-Volatile Compounds in Oiled Impaction Substrates: Measurement of Pyrene Absorption

The use of multi-channel silicone rubber traps as denuders for polycyclic aromatic hydrocarbons

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