Stefania Gilardoni Italian National Research Council Institute of Atmopsheric Sience and Climate (CNR ISAC)

Transcription

1 Aerosol Mass Spectrometry (AMS) for the study of the chemical composition of the particulate matter and the characterisation of organic aerosol with high time resolution Stefania Gilardoni Italian National Research Council Institute of Atmopsheric Sience and Climate (CNR ISAC) TECH-AIR 216, Lecce

2 Outline: The relevance of PM 1 Aerosol Mass Spectrometry (AMS) to study PM 1 properties How AMS compares with traditional techniques? AMS applications: investigation of OA properties and sources

3 Atmospheric particulate matter Solid and liquid particles suspended in the atmosphere with a residence time of hours weeks. Par-cle$ loading$ $ #$cm 93$ $ μg$m 93 $ Nuclea-on$ mode$ Aitken$ mode$ Accumula-on$ mode$ Coarse$ mode$ Number$size$distribu-on $ Mass$size$distribu-on $ 1$nm$ 1$nm$ 1$μm$ 1$μm$ Par-cle$size$

4 Atmospheric particulate matter Visibility reduction Health impairement (kiesewetter et al., 215) Solid and liquid particles suspended in the atmosphere with a residence time of hours weeks. Climate direct and indirect effects (IPCC 27) Par-cle$ loading$ $ #$cm 93$ $ μg$m 93 $ Nuclea-on$ mode$ Aitken$ mode$ Accumula-on$ mode$ Coarse$ mode$ Number$size$distribu-on $ Mass$size$distribu-on $ 1$nm$ 1$nm$ 1$μm$ 1$μm$ Par-cle$size$

5 Atmospheric particulate matter Visibility reduction Health impairement (kiesewetter et al., 215) Solid and liquid particles suspended in the atmosphere with a residence time of hours weeks. Climate direct and indirect effects (IPCC 27) PM 2.5 PM 2.5 EU AQ directive limits: 25 µg m -3 yearly average WHO guidelines: 1 µg m -3 yearly average

6 Climate research IPCC report, 27

7 Climate research Light absorbing organic aerosol - size distribution Light absorption Mm -1 Urban Rural The size distribution of anthropogenic light absorbing species is centered in submicron particle mode. Liu et al., 213 ACP

8 Climate research CCN size distribution for different plume types The size distribution of anthropogenic light absorbing species is centered in submicron particle mode. Submicron particles acts as CCN, contributing to indirect climate effects. Dusek et al., 26 Science

9 AQ research Mineral dust Sea Secondary inorganic aerosol Elemental Carbon + Organic Mass Trace elements Unaccounted mass! 1% 14% 13% 1% 18% 12% 39% 1% 11% 3% 1% 33% 9% 63% 27% 3% 51% PM PM PM 1 PM PM PM 1 Mean annual composition PM in an urban background site in Barcelona. Adapted from Perez et al. 21, AST. Anthropogenic species are mainly in submicron particles, while supermicron particles are dominated by dust. PM 1 could be a better indicator of AQ control measure efficicency.

10 AQ research Mass concentration (ug m -3 ) 1 5 Unac NH4 NO3 SO4 Org EC PM1 PM2.5-1 Average PM1 composition and comparison of organic and sulfate concentration in PM1 and PM2.5 in Bologna during summer 212 Anthropogenic species are mainly in submicron particles, while supermicron particles are dominated by dust. PM 1 could be a better indicator of AQ control measure efficicency.

11 Characterization of submicron particles Whish List: Chemical composition at high time resolution.

12 Characterization of submicron particles Aerosol mass Whish List: spectrometry Chemical composition at high time resolution. Concentration (µg m -3 ) Org NO3 NH4 SO4 Chl µg /m Time resolution: from minutes to seconds Diurnal Hour

13 Characterization of submicron particles Aerosol mass Whish List: spectrometry Chemical composition at high time resolution. High sensitivity. Concentration (µg m -3 ) Org NO3 NH4 SO4 Chl µg /m LOD Org =.4 µg m -3 SO 4 2- =.6 µg m -3 NO 3- =.6 µg m -3 NH 4 + =.8 µg m -3 Cl - =.2 µg m -3 Diurnal Hour

14 Characterization of submicron particles Aerosol mass Whish List: spectrometry Chemical composition at high time resolution. High sensitivity. Size distribution of single chemical species. dm/dlog1d va (µg m -3 ) Org NO 3 - SO 4 2- NH 4 + Cl D va (nm)

15 Characterization of submicron particles Aerosol mass Whish List: spectrometry Chemical composition at high time resolution. High sensitivity. Size distribution of single chemical species. Properties of organic aerosol (such as hygroscopicity, OM/ OC, elemental composition) signal intensity m/z O/C OM/OC Cx CxHy CxHyOz CxHyNp CxHyOzNp 8

16 HR-TOF-AMS

17 Particle Beam Generation Ultrasonic expansion 1-5 Torr Aerodynamic Lens (2 Torr) Particle Inlet (1 atm) Pump Pump Pump Jayne et al., Aerosol Science and Technology 33:1-2(49-7), 2. De Carlo et al., Analitycal Chemistry, 78: , 26

18 Particle Beam Generation Aerodynamic Lens (2 Torr) Particle Inlet (1 atm) CE/Transmission Losses controlled by browninan diffusion and geometry Ultrasonic expansion 1-5 Torr Aerodynamic Size Losses controlled by pinhole and geometry Target Pump Pump Pump Jayne et al., Aerosol Science and Technology 33:1-2(49-7), 2. De Carlo et al., Analitycal Chemistry, 78: , 26

19 Particle Beam Generation 1-5 Torr Aerodynamic Sizing Beam Chopper 1-7 Torr TOF Region Aerodynamic Lens (2 Torr) Particle Inlet (1 atm) Pump Pump Pump Jayne et al., Aerosol Science and Technology 33:1-2(49-7), 2. De Carlo et al., Analitycal Chemistry, 78: , 26

20 MCP Particle Composition Reflectron Hardmirror 1-8 Torr Particle Beam Generation 1-5 Torr Aerodynamic Sizing Beam Chopper 1-7 Torr R + Extraction region Aerodynamic Lens (2 Torr) Particle Inlet (1 atm) TOF Region Pump Pump Pump Thermal Vaporization (6 C) & EI ionization (7 ev) Jayne et al., Aerosol Science and Technology 33:1-2(49-7), 2. De Carlo et al., Analitycal Chemistry, 78: , 26

21 Comparison with traditional techniques: chemical composition AMS (µg m -3 ) Sulfate Ammonium Supersito campaign: November 211 Rural site, San Pietro Capofiume IC (µg m -3 ) Nitrate 4 8 IC (µg m -3 ) 12 AMS (µg m -3 ) IC (µg m -3 ) 3

22 Comparison with traditional techniques: Mass closure Concentration (µg m -3 ) NH4_CDCE_corr NO3_CDCE_corr Org_CDCE_corr SO4_CDCE_corr Chl_CDCE_corr Pegasos campaign: June-July 212 Urban site, Bologna PM1_AMS + EC Date and Time r 2 =.622 Slope %# 9%# PM 1 Campaign average 8%# 5%# 24%# PM1_beta att

23 Concentration < 1µm (µg m -3 ) Comparison with traditional techniques: Chemical composition OA 8 12 Concentration < 1µm (µg m -3 ) Sulfate Pegasos campaign: June-July 212 Urban site, Bologna Concentration < 2.5 µm (µg m -3 ) Concentration < 2.5 µm (µg m -3 ) Concentration < 1µm (µg m -3 ) Nitrate Concentration < 2.5 µm (µg m -3 )

24 signal intensity Comparison with traditional techniques: OA oxidation state HR-TOF-AMS Cx CxHy CxHyOz CxHyNp CxHyOzNp 2 1 H:C O:C OM:OC Pegasos campaign: June-July 212 Urban site, Bologna. 2 4 m/z Fourier Transform Infrared spectrometry FTIR 11/16/11 11/21/11 11/26/11 12/1/11 C-H Organic Aerosol Composition -OH Absorbance a.u. Wavenumber cm -1 -NH -COOH

25 Comparison with traditional techniques: OA oxidation state Org AMS (µg m -3 ) O/C AMS.6.4 Ambient Aiken algorithm Pegasos campaign: June-July 212 Urban site, Bologna Org FTIR (µg m -3 ) O/C FTIR

26 Comparison with traditional techniques: OA oxidation state Org AMS (µg m -3 ) O/C AMS.6.4 Ambient Aiken algorithm Aiken Improved algorithm Pegasos campaign: June-July 212 Urban site, Bologna Org FTIR (µg m -3 ) O/C FTIR

27 AMS applications: PM 1 properties

28 Concentration (µg m -3 ) Particle hygroscopicity Org - NO Supersito campaign: November 211 Rural site, San Pietro Capofiume Scavenging efficiency for each size bin, for each fog event: NO 3 - Scavening Efficiency Ev_2 Ev_8 Ev_3 Ev_9 Ev_4 Ev_11 Ev_5 Ev_12 Ev_ D va (nm) Gilardoni et al. 214, ACP.

29 Concentration (µg m -3 ) Particle hygroscopicity Org - NO Supersito campaign: November 211 Rural site, San Pietro Capofiume Hygroscopicity, mainly driven by OA mass fraction, explains the variability of nitrate scavenging <3nm. scavenging efficiency NO nm 199 nm 24 nm 292 nm 36 nm 445 nm 556 nm...5 Organic mass fraction slope:.6 ±.2 r 2 :.19 slope: 2.1 ±.6 r 2 :.44 slope: 3.3±.9 r 2 : Hygroscopicity (kappa) Gilardoni et al. 214, ACP.

30 OA sources Positive Matrix Factorization (PMF) analysis of OA mass spectra Cx CH CHO1 CHOgt1 CHN CHO1N x HOA OOA1 signal intensity OOA m/z x BBOA 2 4 m/z 6 8 1

31 OA sources Positive Matrix Factorization (PMF) analysis of OA mass spectra Cx CH CHO1 CHOgt1 CHN CHO1N x1-3 x HOA OOA1 OOA2 BBOA signal intensity signal intensity.6.6 Cx.6 CxHy.4.6 CxHyOz Cx.4 CxHyNp.6 CxHyOz CxHyOzNp Cx.4 CxHyNp.2.6 CxHyOz CxHyOzNp Cx.4 CxHyNp.2.6 CxHyOz CxHyOzNp Cx.4 CxHyNp CxHyOz.2 CxHyOzNp Cx..4 CxHyNp CxHyOz CxHyOzNp CxHyNp CxHyOz m/z CxHyOzNp CxHyNp m/z CxHyOzNp m/z m/z m/z m/z signal intensity signal intensity signal intensity signal intensity signal intensity m/z 2 4 m/z Source identification is based on source profile spectra libraries, diurnal trend, correlation of contribution time trend with external tracers (i.e. BC, levoglucosan, Nox )

32 OA sources Relative source contribution Europe: Oxidized Organic Aerosol OOA accounts for more than 5% of OA mass.. Barcelona Helsinki Cabauw K-Puszta Melpitz Montseny Payerne Puijo SPC Vavihill Chilbolton Harwell Finokalia Hyytiälä Mace Head Puy de Dome Jungfraujoch Crippa et al. 214, ACP.

33 OA sources Bottom-up budget: 12-7 Tg SOA per year Smog chamber yields. Top-down budget: 5-45 Tg SOA per year Ground based and satellite observations Reactions take place in atmospheric water. After water evaporation the particle left is enriched in aqsoa. Models Observations Tg of SOA per year Kanakidou 25 Heald 21 HC(g) HC HC(p) R aqsoa

34 OA sources: aqsoa O:C =.66 H:C = 1.36 O:C =.44 H:C = 1.43 OOA I OOA II Supersito campaign: Winter 213 Urban site Concentration (µg m -3 ) Fraction of signal O:C =.57 H:C = 1.55 O:C =.22 H:C = 1.6 OOA III BBOA O:C =.8 H:C = 1.85 HOA Date and time m/z 8 1 Gilardoni et al. 216, PNAS.

35 OA sources: aqsoa O:C =.66 H:C = 1.36 O:C =.44 H:C = 1.43 OOA I OOA II Supersito campaign: Winter 213 Urban site, bologna Concentration (µg m -3 ) Fraction of signal O:C =.57 H:C = 1.55 O:C =.22 H:C = 1.6 OOA III BBOA aqsoa O:C =.8 H:C = 1.85 HOA Date and time m/z 8 1 Gilardoni et al. 216, PNAS.

36 OA sources: aqsoa ug m Date and time Fraction of signal m/z O:C =.56 H:C = Gilardoni et al. 216, PNAS.

37 OA sources: aqsoa HMS signal (a.u.) ug m Date and time Fraction of signal H H 4 6 m/z C=O + O:C =.56 H:C = O=S 1 Aqueous phase O - H O HO C O S O - O H - At ph>5 Time series of hydroxymethanesulfonate (HMS), a proxy of aqueous phase chemistry. H HO C H Aerosol phase O O S O - Gilardoni et al. 216, PNAS.

38 OA sources: aqsoa HMS signal (a.u.) ug m Date and time Fraction of signal O:C =.57 O:C =.56 H:C = m/z O:C = m/z Time series of hydroxymethanesulfonate (HMS), a proxy of aqueous phase chemistry. Mass spectrum of aqsoa after fog dissipation Gilardoni et al. 216, PNAS.

39 OA sources: aqsoa HMS signal (a.u.) ug m Date and time Fraction of signal m/z 4 6 m/z O:C =.56 H:C = aqsoa (µg m -3 ) ALWC (µg m -3 ) 1 Time series of hydroxymethanesulfonate (HMS), a proxy of aqueous phase chemistry. Mass spectrum of aqsoa after fog dissipation aqsoa correlates with ALWC with r =.73 (p<.1) Gilardoni et al. 216, PNAS.

40 A different approach: Offline analysis of OA component Drier CPC HR-TOF-AMS PMF analysis Atomizer Extraction in water (ultrasonic bath) Sample collection

41 A different approach: Offline analysis of OA dissolved in fog water Drier CPC HR-TOF-AMS Atomizer.1.5 Mass spectra of organics dissolved in fog water m/z 8 1

42 Conclusions: Aerosol Mass Spectrometry is an advanced research tool to investigate PM1 chemical and microphysical properties at high time resolution. AMS offers insights into OA properties and sources. AMS can be applied for off-line analysis, to different matrices. As a research tool. work I still in progress.

43 Thanks for your attention This study was supported by the Regional Environmental Protection Agencies of Emilia Romagna, as part of the Supersito project (DRG n. 428/1), This work was supported by the projects PE-GASOS and BACCHUS funded by the European Commission under the Framework Programme 7 (FP7-ENV ).

44 Thanks for your attention ISAC-CNR Marco Paglione, Lara Giulianelli, Claudio Carbone, Matteo Rinaldi, Silvia Sandrini, Sandro Fuzzi, Maria Cristina Facchini. SCRIPPS Instiution of Oceanography UCSD : Lynn Russell EPA of Emilia Romagna Fabiana Scotto,, Vanes Poluzzi, Dimitri Bacco, Arianna Tenitini. Aerodyne Research: Paola Massoli, Manjula Canagaratna

45 Thanks for your attention