title: Real-time continuous characterization of secondary organic aerosol derived from isoprene epoxydiols in downtown Atlanta, Georgia, using the Aerodyne Aerosol Chemical Speciation Monitor.
abstract: Real-time continuous chemical measurements of fine aerosol were made using an Aerodyne Aerosol Chemical Speciation Monitor (ACSM) during summer and fall 2011 in downtown Atlanta, Georgia. Organic mass spectra measured by the ACSM were analyzed by positive matrix factorization (PMF), yielding three conventional factors: hydrocarbon-like organic aerosol (HOA), semivolatile oxygenated organic aerosol (SV-OOA), and low-volatility oxygenated organic aerosol (LV-OOA). An additional OOA factor that contributed to 33 ± 10% of the organic mass was resolved in summer. This factor had a mass spectrum that strongly correlated (r(2) = 0.74) to that obtained from laboratory-generated secondary organic aerosol (SOA) derived from synthetic isoprene epoxydiols (IEPOX). Time series of this additional factor is also well correlated (r(2) = 0.59) with IEPOX-derived SOA tracers from filters collected in Atlanta but less correlated (r(2) < 0.3) with a methacrylic acid epoxide (MAE)-derived SOA tracer, α-pinene SOA tracers, and a biomass burning tracer (i.e., levoglucosan), and primary emissions. Our analyses suggest IEPOX as the source of this additional factor, which has some correlation with aerosol acidity (r(2) = 0.3), measured as H(+) (nmol m(-3)), and sulfate mass loading (r(2) = 0.48), consistent with prior work showing that these two parameters promote heterogeneous chemistry of IEPOX to form SOA.
authors: Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States.
authors: Sri Hapsari
authors: SH
authors: Budisulistiorini
authors: Manjula R
authors: MR
authors: Canagaratna
authors: Philip L
authors: PL
authors: Croteau
authors: Wendy J
authors: WJ
authors: Marth
authors: Karsten
authors: K
authors: Baumann
authors: Eric S
authors: ES
authors: Edgerton
authors: Stephanie L
authors: SL
authors: Shaw
authors: Eladio M
authors: EM
authors: Knipping
authors: Douglas R
authors: DR
authors: Worsnop
authors: John T
authors: JT
authors: Jayne
authors: Avram
authors: A
authors: Gold
authors: Jason D
authors: JD
authors: Surratt
mesh_terms: D000336:Aerosols / Q000032:analysis*; D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D001272:Atmosphere; D000081008:Bicyclic Monoterpenes; D002070:Butadienes / Q000737:chemistry*; D002947:Cities; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods*; D004852:Epoxy Compounds / Q000737:chemistry*; D005845:Georgia; D045782:Hemiterpenes / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods / Q000592:standards; D039821:Monoterpenes / Q000737:chemistry; D010420:Pentanes / Q000737:chemistry*; D012015:Reference Standards; D012621:Seasons
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D000081008:Bicyclic Monoterpenes; D002070:Butadienes; D004852:Epoxy Compounds; D045782:Hemiterpenes; D039821:Monoterpenes; D010420:Pentanes; C005059:isoprene; C005451:alpha-pinene