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Seasonal and Diurnal Variations of Particulate Organosulfates in Urban Shanghai, China

Seasonal and Diurnal Variations of Particulate Organosulfates in Urban Shanghai, China. 2nd SINO FINNISH WORKSHOP ON AEROSOL SCIENCE AND TECHNOLOGY. Ye Ma, Xinkai Xu , Weihua Song, Fuhai Geng , Lin Wang.

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Seasonal and Diurnal Variations of Particulate Organosulfates in Urban Shanghai, China

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  1. Seasonal and Diurnal Variations of Particulate Organosulfates in Urban Shanghai, China 2nd SINO FINNISH WORKSHOP ON AEROSOL SCIENCE AND TECHNOLOGY Ye Ma, XinkaiXu, Weihua Song, FuhaiGeng, Lin Wang Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3) Department of Environmental Science & Engineering, Fudan University, Shanghai, China August 15, 2013

  2. Background Organosulfates (OSs, ROSO3H), normally recognized as sulfate esters and their derivatives, help to reconcile the gap between measured and calculated SOAs. • OSs can be formed from: • Reactions between oxidation products of biogenic VOCs and sulfuric acid or sulfate aerosols. • [Surratt et al., 2007, ES&T; Gomez-Gonzalez et al., 2008, J. Mass. Spectrom. ; Surratt et al., 2008, J. Phys. Chem. A.] • Reactive uptake of carbonyl compounds on sulfuric acid or sulfate aerosols. • [Liggio et al., 2005, ES&T; Liggio and Li, 2006a, J. Geophys. Res.; Liggio and Li, 2006b, Geophys. Res. Lett.]

  3. α -pinene Isoprene rainwater β -pinene limonene Aerosols Southeastern US. & Europe & Asia Southeastern US. & Europe & Asia Surratt et al., 2008, J. Phys. Chem. A Gomez-Gonzalez et al., 2008, J. Mass. Spectrom Stone et al., 2012, Atmos. Environ. Surratt et al., 2008, J. Phys. Chem. A Gomez-Gonzalez et al., 2008, J. Mass. Spectrom Lin et al., 2012, ES&T. Southeastern US. & Europe & Asia Southeastern US. & Europe & Asia Iinuma et al., 2007, ES&T. Surratt et al., 2008, J. Phys. Chem. A Lin et al., 2012, ES&T. Iinuma et al., 2007, ES&T. Surratt et al., 2008, J. Phys. Chem. A Stone et al., 2012, Atmos. Environ. Rainwater & Fog Organosulfates formed from α –terpinene and β –caryophyllene have recently been identified in ambient aerosols in Asia. OSs of isoprene & monoterpene Stone et al., 2012, Atmos. Environ. Lin et al., 2012, ES&T. Altieri et al., 2009, Atoms. Chem. Phys. Mazzoleni et al., 2010, ES&T.

  4. Analytical methods for quantification • Direct techniques: • LC-MS/MS • (authentic / synthesized standards) • Indirect techniques: • FT-ICRMS • X-ray fluorescence spectroscopy & Ion Chromatography Identification and quantification of biogenic and aromatic OSs in an urban area with high particle loading like Shanghai

  5. Experimental A Teflon chamber, 4.8 m3 • SMPS • CIMS • NO-NO2-NOx / O3 analyzer • Chamber experiments: • α-pinene + CH3ONO + NO + seed particles; • (2) β-pinene + CH3ONO + NO + seed particles; • (3) isoprene + CH3ONO + NO + seed particles

  6. Smog chamber samples and ambient PM2.5 samples were analyzed by an HPLC/(-) ESI- Triple Quadrupole-MS. • Surrogate standards: sodium octyl sulfate & camphorsulfonic acid → biogenic OSs; • Synthesized standard: benzyl sulfate → aromatic OS • benzyl alcohol + diisopropylethyl amine +chlorosulfonic acid

  7. Identification of OSs Figure 1. Total ion chromatogram (TIC) under MRM mode obtained from β-pinene /methylnitrite/NO/highly acidic seed chamber experiment. Chromatographic peaks are marked with corresponding [M-H]- ions based on previous studies (Surratt et al., 2008, J. Phys. Chem. A; Kundu et al., 2012, Atmos. Chem. Phys.)

  8. OSs in urban Shanghai Apr. , Jul., Oct.2012, & Jan. 2013 OSs of Isoprene: m/z 331 : C10H19O10S- m/z 215 : C5H11O7S- m/z 213 : C5H9O7S- m/z 153 : C3H5O5S- OS of aromatics: m/z 187 : C7H7O4S- OSs of α-/β-pinene: m/z 326 : C10H16NO9S- m/z 310 : C10H16NO8S- m/z 294 : C10H16NO7S- m/z 283 : C10H19O7S- m/z 281 : C10H17O7S- m/z 279 : C10H15O7S- m/z 265 : C10H17O6S- m/z 263 : C10H15O6S- m/z 249 : C10H17O5S- m/z 247 : C10H15O5S- m/z 237 : C8H13O6S- m/z 223 : C7H11O6S- • On average: • The total concentrations of OSs: 0.02-53.2 ng m-3 • The highest concentration of an individual OS: 43.3 ng m-3 (m/z 215)

  9. Seasonal profiles of OSs Figure 2. Seasonal variation of organosulfates categorized into isoprene-derived organosulfates (IOS), α/β-pinene-derived organosulfates (POS), and benzyl sulfate (BS). The data shown was obtained using sodium octyl sulfate and benzyl sulfate as standards for quantification.

  10. All OSs: highest in summer (23 ng m-3) , all OSs/ PM2.5→4.1×10-2%; • lowest in spring (0.45 ng m-3), all OSs/ PM2.5→8.5×10-4%. • OSs are unlikely a key component of PM2.5 in Shanghai, a typical urban area. • IOSs: highest in summer (19.9 ng m-3), IOSs/all OSs →86.6% . • POSs:highest in summer (2.4 ng m-3), POSs/all OSs →only 10%. • BS: less fluctuant, BS/all OSs →64% in winter but only 3.0% in summer; • average BS/ PM2.5→8×10-4%, an order of magnitude higher than that in • Lahore, Pakistan (Kundu et al., 2012, Atmos. Chem. Phys.).

  11. Diurnal profiles of OSs-IOSs Figure 3. Seasonal and diurnal variations of individual OSs. (a) m/z 215 IOS; (b) m/z 331, m/z 153, and m/z 231 IOSs. IOSs were generally more prevalent during the day, suggesting that photooxidation of isoprene is its major formation pathway.

  12. Diurnal profiles of OSs-POSs Figure 3. Seasonal and diurnal variations of individual OSs. (c) m/z 249 and m/z 263 POSs.

  13. m/z 249 POSs α-pinene+OH/NO3 +seed particles At night, m/z 249a+ m/z 249b decreased by 20-70%. m/z 249a m/z 249b β-pinene+ OH/NO3/O3+ seed particles At night, m/z 249c increased by 50-90%. β-pinene+ OH/NO3+ seed particles At night, m/z 249d increased by 20-60%. m/z 249c m/z 249d NO3 radical and O3 chemistry were effective pathways for the formation of m/z 249 POSs at night. (Iinuma et al., 2007b, ES&T.; Surratt et al., 2008, J. Phys. Chem. A.)

  14. m/z 263 POS β-pinene+OH/O3+seed particles On most sampling days, concentration of m/z 263 at night was 1-8 times higher. O3 chemistry was an effective pathways for the formation of m/z 263 POS at night. (Iinuma et al., 2007b, ES&T.; Surratt et al., 2008, J. Phys. Chem. A.)

  15. Nitrooxy-OSs (POSs) Figure 3. Seasonal and diurnal variations of individual OSs. (d) m/z 294, m/z 310, and m/z 326 POSs

  16. m/z 294 POS The most abundant nitrooxy-OS in Shanghai as well as in Europe, US and Asia. (Gomez-Gonzalez et al., 2012, Atmos. Chem. Phys.; Worton et al., 2011, Atmos. Chem. Phys.; Lin et al., 2012, ES&T.) m/z 294a m/z 294b m/z 294c (Surratt et al., 2008, J. Phys. Chem. A.) NO3 chemistry likely contributed to the formation of m/z 294c at night.

  17. Other POSs m/z 283 & m/z 281 from α-/β-pinene, and m/z 265, m/z 247, m/z 237 and m/z 223 POSs were only detected in Asian locations. (this study and Lin et al., 2012, ES&T) Figure 3. Seasonal and diurnal variations of individual OSs. (e) m/z 283, m/z 279, m/z 265, m/z 247, m/z 237, m/z 281, and m/z 223 POSs;

  18. Diurnal profiles of BS m/z 187 Precursor: aromatics Formation: OH? NO3? Figure 3. Seasonal and diurnal variations of individual OSs. (f) m/z 187 BS.

  19. OSs and gas-phase pollutants Figure 4. Diurnal variations of OSs, PM2.5, OSs/PM2.5, SO2, O3, NO, NO2, and NOx during July 12-14, 2012.

  20. Conclusions • Seventeen OSs (4 IOSs+ 12 POSs + BS) were identified and quantified in urban Shanghai, with overall average concentration of 6.45 ng m-3, accounting for 0.084‰ of total PM2.5 mass. • Isoprene- and α-/β-pinene-derived organosulfates dominated in summer, whereas aromatic organosulfate was more prevalent in winter. • Aromatic OS may be an important OS species in urban Shanghai. • Photooxidation is the main driving force for the formation of OSs, but NO3 and O3 at night likely contribute to some OS species, including nitrooxy-OSs.

  21. Acknowledgments • National Natural Science Foundation of China • No. 21107015 & 21222703 • Science & Technology Commission of Shanghai Municipality • No. 11PJ1401100 • Special Fund for Ph.D. Studies from Ministry of Education of China • No. 20120071110023

  22. trimethylamine 2,4 hexadienal ammonia glyoxal Previous NPF Research Experiences

  23. NPF Research at Shanghai

  24. Thank you! Questions?

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