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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

Variation of peak area ratios of targeted PAHs (100 ng injection) relative to the peak area of internal standard (BaPd2) as a function of injection number.
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Related In: Results  -  Collection


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fig2: Variation of peak area ratios of targeted PAHs (100 ng injection) relative to the peak area of internal standard (BaPd2) as a function of injection number.

Mentions: It was found that the more injections of the sample extracts, the more deterioration of peak area counts. The routine injection of the molecular marker mixture after the injection of the sample extract exhibited the sensitivity deterioration (Figure 2). Such sensitivity deterioration was observed only for the PAHs. This deterioration was due to the cross-contamination from the previous injections; residuals of unfavorable matrix in the inlet resulted in inefficient transfer of the PAHs into the GC column. The sensitivity was restored by replacing the GC inlet liner and cutting the tip of GC column. Such maintenance was made after 10–15 measurements of the sample extracts. If necessary, corrections on peak area counts were made using the sensitivity profile shown in Figure 2.


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

Irei S - Int J Anal Chem (2016)

Variation of peak area ratios of targeted PAHs (100 ng injection) relative to the peak area of internal standard (BaPd2) as a function of injection number.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig2: Variation of peak area ratios of targeted PAHs (100 ng injection) relative to the peak area of internal standard (BaPd2) as a function of injection number.
Mentions: It was found that the more injections of the sample extracts, the more deterioration of peak area counts. The routine injection of the molecular marker mixture after the injection of the sample extract exhibited the sensitivity deterioration (Figure 2). Such sensitivity deterioration was observed only for the PAHs. This deterioration was due to the cross-contamination from the previous injections; residuals of unfavorable matrix in the inlet resulted in inefficient transfer of the PAHs into the GC column. The sensitivity was restored by replacing the GC inlet liner and cutting the tip of GC column. Such maintenance was made after 10–15 measurements of the sample extracts. If necessary, corrections on peak area counts were made using the sensitivity profile shown in Figure 2.

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