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Direct Analysis of Low-Volatile Molecular Marker Extract from Airborne Particulate Matter Using Sensitivity Correction Method.

Irei S - Int J Anal Chem (2016)

Bottom Line: Analysis of size-segregated PM filter samples showed that their size distributions were found to be in the PM smaller than 0.4 μm aerodynamic diameter.The observations were consistent with our expectation of their possible sources.Thus, the method was found to be useful for molecular marker studies.

View Article: PubMed Central - PubMed

Affiliation: Centre for Atmospheric Chemistry and Department of Chemistry, York University, 4700 Keels Street, Toronto, ON, Canada M3J 1P3.

ABSTRACT
Molecular marker analysis of environmental samples often requires time consuming preseparation steps. Here, analysis of low-volatile nonpolar molecular markers (5-6 ring polycyclic aromatic hydrocarbons or PAHs, hopanoids, and n-alkanes) without the preseparation procedure is presented. Analysis of artificial sample extracts was directly conducted by gas chromatography-mass spectrometry (GC-MS). After every sample injection, a standard mixture was also analyzed to make a correction on the variation of instrumental sensitivity caused by the unfavorable matrix contained in the extract. The method was further validated for the PAHs using the NIST standard reference materials (SRMs) and then applied to airborne particulate matter samples. Tests with the SRMs showed that overall our methodology was validated with the uncertainty of ~30%. The measurement results of airborne particulate matter (PM) filter samples showed a strong correlation between the PAHs, implying the contributions from the same emission source. Analysis of size-segregated PM filter samples showed that their size distributions were found to be in the PM smaller than 0.4 μm aerodynamic diameter. The observations were consistent with our expectation of their possible sources. Thus, the method was found to be useful for molecular marker studies.

No MeSH data available.


Related in: MedlinePlus

Size distribution of selected molecular marker fractions as a function of size-bin. Ct = the sum of concentrations in all size-bins.
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Related In: Results  -  Collection


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fig5: Size distribution of selected molecular marker fractions as a function of size-bin. Ct = the sum of concentrations in all size-bins.

Mentions: The size distribution of selected molecular marker fractions (dC/Ct, where Ct is the sum of the marker concentrations in all size-bins) observed at the York Gateway tunnel showed that the majority of Cor, abHp, and C22 n-alkane were in the size range smaller than 0.4 μm, while the majority of C29 n-alkane was in the range larger than 0.4 μm (Figure 5). The observations strongly suggest that the origin of Cor, abHp, and C22 n-alkane was vehicular emissions, while the origin of C29 n-alkane was road dust, tire debris, or plant wax from the outside of the tunnel. The observations of these makers at Hamilton showed more complex pattern: abHp at Hamilton showed the major distribution smaller than 0.4 μm, similar to that at the York Gateway tunnel, while Cor and C22 and C29 n-alkanes showed another mode around 1 μm. The different size distribution at Hamilton may suggest input of these markers from other sources or particle growth of fine PM emitted from vehicular emissions. More detailed analysis will be needed to explain the observations.


Direct Analysis of Low-Volatile Molecular Marker Extract from Airborne Particulate Matter Using Sensitivity Correction Method.

Irei S - Int J Anal Chem (2016)

Size distribution of selected molecular marker fractions as a function of size-bin. Ct = the sum of concentrations in all size-bins.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4834413&req=5

fig5: Size distribution of selected molecular marker fractions as a function of size-bin. Ct = the sum of concentrations in all size-bins.
Mentions: The size distribution of selected molecular marker fractions (dC/Ct, where Ct is the sum of the marker concentrations in all size-bins) observed at the York Gateway tunnel showed that the majority of Cor, abHp, and C22 n-alkane were in the size range smaller than 0.4 μm, while the majority of C29 n-alkane was in the range larger than 0.4 μm (Figure 5). The observations strongly suggest that the origin of Cor, abHp, and C22 n-alkane was vehicular emissions, while the origin of C29 n-alkane was road dust, tire debris, or plant wax from the outside of the tunnel. The observations of these makers at Hamilton showed more complex pattern: abHp at Hamilton showed the major distribution smaller than 0.4 μm, similar to that at the York Gateway tunnel, while Cor and C22 and C29 n-alkanes showed another mode around 1 μm. The different size distribution at Hamilton may suggest input of these markers from other sources or particle growth of fine PM emitted from vehicular emissions. More detailed analysis will be needed to explain the observations.

Bottom Line: Analysis of size-segregated PM filter samples showed that their size distributions were found to be in the PM smaller than 0.4 μm aerodynamic diameter.The observations were consistent with our expectation of their possible sources.Thus, the method was found to be useful for molecular marker studies.

View Article: PubMed Central - PubMed

Affiliation: Centre for Atmospheric Chemistry and Department of Chemistry, York University, 4700 Keels Street, Toronto, ON, Canada M3J 1P3.

ABSTRACT
Molecular marker analysis of environmental samples often requires time consuming preseparation steps. Here, analysis of low-volatile nonpolar molecular markers (5-6 ring polycyclic aromatic hydrocarbons or PAHs, hopanoids, and n-alkanes) without the preseparation procedure is presented. Analysis of artificial sample extracts was directly conducted by gas chromatography-mass spectrometry (GC-MS). After every sample injection, a standard mixture was also analyzed to make a correction on the variation of instrumental sensitivity caused by the unfavorable matrix contained in the extract. The method was further validated for the PAHs using the NIST standard reference materials (SRMs) and then applied to airborne particulate matter samples. Tests with the SRMs showed that overall our methodology was validated with the uncertainty of ~30%. The measurement results of airborne particulate matter (PM) filter samples showed a strong correlation between the PAHs, implying the contributions from the same emission source. Analysis of size-segregated PM filter samples showed that their size distributions were found to be in the PM smaller than 0.4 μm aerodynamic diameter. The observations were consistent with our expectation of their possible sources. Thus, the method was found to be useful for molecular marker studies.

No MeSH data available.


Related in: MedlinePlus