Impact of Gas/Particle Partitioning of Semivolatile Organic Compounds on Source Apportionment with Positive Matrix Factorization

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• 作者：Mingjie Xie ; Michael P. Hannigan ; Kelley C. Barsanti
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：August 19, 2014
• 年：2014
• 卷：48
• 期：16
• 页码：9053-9060
• 全文大小：403K
• ISSN：1520-5851

文摘

To quantify and minimize the influence of gas/particle (G/P) partitioning on receptor-based source apportionment using particle-phase semivolatile organic compound (SVOC) data, positive matrix factorization (PMF) coupled with a bootstrap technique was applied to three data sets mainly composed of 鈥渕easured-total鈥?(measured particle- + gas-phase), 鈥減article-only鈥?(measured particle-phase) and 鈥減redicted-total鈥?(measured particle-phase + predicted gas-phase) SVOCs to apportion carbonaceous aerosols. Particle- (PM_2.5) and gas-phase SVOCs were collected using quartz fiber filters followed by PUF/XAD-4/PUF adsorbents and measured using gas chromatography鈥搈ass spectrometry (GC鈥揗S). Concentrations of gas-phase SVOCs were also predicted from their particle-phase concentrations using absorptive partitioning theory. Five factors were resolved for each data set, and the factor profiles were generally consistent across the three PMF solutions. Using a previous source apportionment study at the same receptor site, those five factors were linked to summertime biogenic emissions (odd n-alkane factor), unburned fossil fuels (light SVOC factor), road dust and/or cooking (n-alkane factor), motor vehicle emissions (PAH factor), and lubricating oil combustion (sterane factor). The 鈥渕easured-total鈥?solution was least influenced by G/P partitioning and used as reference. Two out of the five factors (odd n-alkane and PAH factors) exhibited consistent contributions for 鈥減article-only鈥?vs 鈥渕easured-total鈥?and 鈥減redicted-total鈥?vs 鈥渕easured-total鈥?solutions. Factor contributions of light SVOC and n-alkane factors were more consistent for 鈥減redicted-total鈥?vs 鈥渕easured-total鈥?than 鈥減article-only鈥?vs 鈥渕easured-total鈥?solutions. The remaining factor (sterane factor) underestimated the contribution by around 50% from both 鈥減article-only鈥?and 鈥減redicted-total鈥?solutions. The results of this study confirm that when measured gas-phase SVOCs are not available, 鈥減redicted-total鈥?SVOCs should be used to decrease the influence of G/P partitioning on receptor-based source apportionment.