Atmospheric Sub-micron Aerosol Organic:  Results from Aerosol Mass Spectrometry Douglas R. Worsnop, John Jayne, Manjula Canagaratna, Tim Onasch, Hacene Boudries, Leah Williams Aerodyne Research, Inc. Jose Jimenez , Qi Zhang, Peter DeCarlo, Alex Huffman, Alice Delia University of Colorado Rami Alfarra, James Allan, Keith Bower, Hugh Coe UMIST Ann Middlebrook Jay Slowik, Paul Davidovits NOAA Boston College Frank Drewnick, Johannes Schneider Silke Weimer, Ken Demerjian MPI Mainz SUNY Albany European Monitoring and Evaluation Program (EMEP) Workshop on Particulate Matter (PM) Measurement United Nations Economic Commission for Europe New Orleans, Wednesday, April 21, 2004

Aerodyne Aerosol Mass Spectrometer (AMS) Particle Particle Beam Aerodynamic Sizing Composition Generation Quadrupole Mass Spectrometer Chopper Thermal Vaporization & Electron Impact Ionization TOF Region Aerodynamic Lens (2 Torr) Particle Inlet (1 atm) Turbo Pump Turbo Pump Turbo Pump 100% transmission (60-600 nm), aerodynamic sizing, linear mass signal. Jayne et al., Aerosol Science and Technology 33:1-2(49-70), 2000. Jimenez et al., Journal of Geophysical Research, 108(D7), 8425, doi:10.1029 / 2001JD001213, 2003. The particles enter the AMS and are focused by an aerodynamic lens into a tight beam (<1 mm diameter). In the size range 50-1000 nm we get 100% of the particles transmitted from the inlet to the detector. The chopper wheel defines the beginning of a time-of-flight period. Smaller particles move faster, so when a packet travels from chopper to detector, the smallest ones arrive first. The detector consists of a 600 degree C oven that flash vaporizes the particles. The oven is located inside the ionizer region of a quadrupole mass spectrometer. Most of the gas phase molecules are lost in the first chamber of the AMS, so what reaches the ionizer is almost exclusively material that was in the particle phase. Can use single ion monitoring mode to get quantitative information about single particles, or scan the quadrupole to get complete MS of average particles.

AMS: Size Resolved Chemical Composition of Sub-micron aerosol (PM1) Non-refractory (NR) composition (thermal vaporization at 600C) e.g. no black carbon (BC), dust or (typically) seasalt Electron Impact (EI) Mass Spectrometry – quantitative mass loading All NR components detected with little uncertainty direct calibration / chemically unbiased sample Mass spectrum of inorganics and organics easy to separate Analysis of organic matter (OM) – primary vs secondary hydrocarbon (lube oil) vs oxidized (HULIS) direct measure of OM/OC ratio Aerodynamic focusing and sizing collection efficiency  1 for aspherical particles; e.g. (NH4)2SO4 measure CE with beam width probe – particle shape information aerodynamic (AMS) + mobility (SMPS) sizing  particle mass, density, shape and fractal dimension + chemistry

Mass balance –TEOM, PILS, OC/EC Organic classification: primary vs oxidized  OM/OC ratio Sizing – comparison with SMPS ( and Moudi) small, fractal organic vs mixed organic/sulfate accumulation dirunal and seasonal patterns compare to vehicle and dynometer emissions Future: ToF-AMS, higher sensitivity (aircraft time response) and single particle composition “cheaper, simpler” Q-AMS system hour time resolution size binning (<100nm, 100-200 nm, > 200 nm)

Real Time Chemical and Physical Composition of Aerosols Aerosol Sampling Sampling frequency - >10Hz Real-time measurement. AMS Nitrate Sulphate Ammonium Alkanes Organics Aromatics Etc.. Mass distribution Chemical composition

EI Ionization: A + e- ----> A+ ----> ai+ Mass Loading A  (MWA/IEA)  Ion Signal ai Calibration Factor * (MWNO3/IENO3) EI Ionization Cross Sections

Typical ambient aerosol mass spectrum

Group Molecule/Species Ion Fragments Mass Fragments MS Signatures for Aerosol Species Identification color coded to match spectra Water H2O H2O+ , HO+ , O+ 18, 17, 16 Ammonium NH3 NH3+, NH2+, NH+ 17, 16, 15 Nitrate HNO3 HNO3+, NO2+, NO+ 63, 46, 30 Sulfate H2SO4 H2SO4+, HSO3+, SO3+ 98, 81, 80 SO2+, SO+ 64, 48 Organic CnHmOy H2O+, CO+, CO2+ 18, 28, 44 (Oxygenated) H3C2O+, HCO2+, Cn’Hm+ 43, 45, ... Organic CnHm Cn’Hm’+ 27,29,41,43,55,57,69,71... (hydrocarbon) Group Molecule/Species Ion Fragments Mass Fragments e- Standard electron impact ionization @ 70 eV Easy to quantify: ca. NIST MS library Easy to separate inorganic and organic components Speciation of organic composition is challenging

Comparison of PMTACS’01 and PMTACS’04 Time Series, Diurnal Plots, and Data Diagnostics Silke Weimer+, Frank Drewnick‡, Doug Worsnop*, Ken Demerjian+ + Atmospheric Sciences Research Center, Albany/NY, ‡ MPI for Chemistry, Mainz; *Aerodyne Res. Inc./Billerica/MA

Speciated Mass, Queens, NY Mass Balance AMS vs.TEOM Speciated Mass, Queens, NY The “Other” Category -PM1 vs PM2.5 -elemental carbon -crustal oxides Drewnick et al, 2003 F. Drewnick, J. Schwab, K. Demerjian ASRC SUNY Albany

Comparison of FDMS and AMS, PMTACS04 PRELIMINARY WINTER AMS/FDMS ~ 0.7 for AMS Particle Collection Efficiency: CE = 0.5 FDMS – Dirk Felton, NYSDEC

10 minute data in PMTACS04 PRLIMINARY ESTIMATED Primary organic Oxidized organic Plumes of primary organic are clearly observed - due to vehicles driving by the site (frequency increased after college re-opened in last week of study) Weimer, Drewnick et al

CnHmOy ----> H2O+ CO+ CO2+ C2H3O+ Organic Mass Spectra e- CnHm ----> Cn’Hm’+ 27, 29, 41, 43, 55, 57, 69, 71, ... C4H9+ CnHmOy ----> H2O+ CO+ CO2+ C2H3O+ 18 28 44 43 27, 29, 55, …. Following flash vaporization at ~600C

Diurnal Cycles of OM Classes Weimer, Drewnick et al Summer 57 – primary marker Winter 44 – oxidized marker

Aerosol Size-Resolved Composition with the Aerodyne AMS in Pittsburgh Jose-Luis Jimenez*, Qi Zhang, Manjula Canagaratna, John Jayne, Doug Worsnop, Charles Stanier, Spyros Pandis *Dept. Chemistry & CIRES University of Colorado at Boulder EPA Supersite Meeting Feb. 26, 2004

Diesel Vehicle Exhaust Primary Organic Component in Pittsburgh Zhang, Jimenez et al. Diesel Vehicle Exhaust Jayne, Canagaratna et al.

Oxidized Organic Component in Pittsburgh Fulvic Acid “HULIS” ???? Zhang, Jimenez et al. Fulvic Acid “HULIS” ???? Rami Alfarra et al (UMIST)

Total Organics Quantitation vs. Sunset Labs OC Pittsburgh “Super Site” OM / OC ~ 1.7 Total Organic = C  (all organic ions) Qi Zhang, Jose Jimenez, CU

FUTURE IDEAS  lower cost “Cheaper” AMS – smaller, no fast electronics, limited size binning approaching cost and operational equivalent of RGA or GCMS simple calibration system? cost equivalent to collection of individual continuous instruments add thermal denuder to evaluate semivolatile component Aerosol Collection (with aerodynamic lens) (Paul Ziemann) – in situ (EI) mass spectrometric analysis - separation via volatility aerosol collection (< 1 hour) [ Hacene Boudries ] for direct injection into speciation detectors e.g. GCMS, PTRMS

Acknowledgments Support: NSF, ONR, DoE EPA, NASA, NOAA, JARI Aerodyne Doug Worsnop John Jayne Manjula Canagaratna Hacene Boudries Tim Onasch Phil Mortimer Leah Williams Boston College Jay Slowik Paul Davidovits Arizona State Jonathan Allen Utah State Phil Silva JAPAN Nobu Tagekawa (Tokyo) Yutake Kondo (Tokyo) Akinori Takami (NIES) Akio Shimono (Sanyu) Ken-ichi Akiyama (JARI) Boulder Jose Jimenez (UC) Alice Delia, Darren Toohey Ann Middlebrook (NOAA) Qi Zhang, Peter Decarlo (UC) Alex Huffman, Katja Dzepina Caltech John Seinfeld, Rick Flagan Roya Bahreini Environment Canada Shao Meng Li, Jeff Brook Kathy Hayden, Gang Lu, Richard Leaitch SUNY Albany Ken Demerjian Wyoming Peter Liu Derek Montague PNNL / BNL Carl Berkowitz, Pete Daum UMIST Hugh Coe Keith Bower Paul Williams James Allen Rami Alfarra MPI Mainz Frank Drewnick Johannes Schneider Stephan Borrmann Joachim Curtius CEH (Edinburgh) Eiko Nemitz David Anderson KFA Juelich Thomas Mentel Andreas Wahner MIT Xuefeng Zhang Ken Smith TOFWERK Marc Gonin Katrin Fuhrer Support: NSF, ONR, DoE EPA, NASA, NOAA, JARI Environment Canada