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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

(a) Total ion chromatogram by Scan for the July 13 sample at Simcoe; (b) m/z 191 ion chromatogram by SIM for June 1 at York Gateway tunnel; (c) m/z 191 ion chromatogram by SIM for June 23 at Hamilton.
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fig3: (a) Total ion chromatogram by Scan for the July 13 sample at Simcoe; (b) m/z 191 ion chromatogram by SIM for June 1 at York Gateway tunnel; (c) m/z 191 ion chromatogram by SIM for June 23 at Hamilton.

Mentions: The analysis of ambient sample extracts demonstrated the usefulness of the methodology for the molecular marker analysis. Many chromatograms obtained from the analysis of filter samples collected at Hamilton and some from those collected at Simcoe showed a hump attributing to an unresolved complex mixture or UCM (Figure 3(a)). The hump is an indication of organics from fossil fuel combustion [13]. Indeed, the m/z 191 ion chromatograms for hopanes, molecular markers for fossil fuel combustion (Figure 3(b)), also showed detection of those marker substances (Figure 3(c)). In addition, the PAH analysis also demonstrated that the BaP concentrations observed at the two locations in the southern Ontario and the York Gateway tunnel were highly correlated with the Ind concentrations (Figure 4). The coefficient of determination for the linear regression from all the data points was 0.997. Such high correlations were observed between the molecular markers in the same family only (i.e., between the PAHs, hopanoids, or n-alkanes), probably due to different production processes [14]. This high correlation suggests that these PAHs can be used as source identification of vehicular emissions. Even though the plot is not shown, high correlation was observed between hopane series as well.


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

Irei S - Int J Anal Chem (2016)

(a) Total ion chromatogram by Scan for the July 13 sample at Simcoe; (b) m/z 191 ion chromatogram by SIM for June 1 at York Gateway tunnel; (c) m/z 191 ion chromatogram by SIM for June 23 at Hamilton.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig3: (a) Total ion chromatogram by Scan for the July 13 sample at Simcoe; (b) m/z 191 ion chromatogram by SIM for June 1 at York Gateway tunnel; (c) m/z 191 ion chromatogram by SIM for June 23 at Hamilton.
Mentions: The analysis of ambient sample extracts demonstrated the usefulness of the methodology for the molecular marker analysis. Many chromatograms obtained from the analysis of filter samples collected at Hamilton and some from those collected at Simcoe showed a hump attributing to an unresolved complex mixture or UCM (Figure 3(a)). The hump is an indication of organics from fossil fuel combustion [13]. Indeed, the m/z 191 ion chromatograms for hopanes, molecular markers for fossil fuel combustion (Figure 3(b)), also showed detection of those marker substances (Figure 3(c)). In addition, the PAH analysis also demonstrated that the BaP concentrations observed at the two locations in the southern Ontario and the York Gateway tunnel were highly correlated with the Ind concentrations (Figure 4). The coefficient of determination for the linear regression from all the data points was 0.997. Such high correlations were observed between the molecular markers in the same family only (i.e., between the PAHs, hopanoids, or n-alkanes), probably due to different production processes [14]. This high correlation suggests that these PAHs can be used as source identification of vehicular emissions. Even though the plot is not shown, high correlation was observed between hopane series as well.

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