Aerosol Chemical Composition Using Aerosol Mass Spectrometry
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Aerosol Chemical Composition Using Aerosol Mass Spectrometry
ASCOS WorkshopLandskronaApril 9, 2008
R. Chang, J. Abbatt – University of TorontoK. Hayden, R. Leaitch, S.-M. Li, J. Liggio – Environment Canada
Objectives• characterize composition of surface aerosols
– physical properties, hygroscopic properties• source of air
– local natural aerosol• Does it correlate with biological activity?• Is there an organic component?• Are the aerosols neutralized? Is there enough ammonia
present?• Is there MSA in the aerosol?
– transported anthropogenic aerosol• Are the aerosols neutralized?• Is there an organic component?
Time-of-Flight Aerosol Mass Spectrometer
Mass Spectrum Mode
SOLAS 2007 in Canadian Arctic0.4
0.3
0.2
0.1
0.0
µg/m
3
12:00 AM12/10/2007
12:00 PM 12:00 AM13/10/2007
12:00 PM
Date and Time
Clean 2
Clean 1
OrganicNitrateSulphateAmmoniumChloride
10-5
10-4
10-3
10-2
10-1
100
101
102
Nitr
ate
equi
vale
nt m
ass
(µg
m-3
)
20015010050m/z
MSSD all 109.751 MSSD Air 108.976 MSSD Water 0.303935 MSSD NO3 0.0117742 MSSD SO4 0.0689265 MSSD Org 0.118997 MSSD NH4 0.0403764 MSSD Chl -0.00177612
Clean 1
800
600
400
200
dN/d
logD
p2 3 4 5 6 7
1002 3 4 5
Dmobility (nm)
0.8
0.6
0.4
0.2
0.0
dV/dlogD
p
Number
Volume
Sulphate MS Neutralized
Clean 1
20
15
10
5
0
x10-3
12010080604020
0.00
NISTH2SO4
Time-of-Flight Aerosol Mass Spectrometer
Particle Time of Flight Mode(PToF)
PToF Distribution in Southern Ontario
12
10
8
6
4
2
0
µg/m
3
101 102 103 104
PToF size, nm
ug_log_Orgav_temp ug_log_NO3av_temp ug_log_SO4av_temp ug_log_NH4av_temp ug_log_Chlav_temp
Sulphate OrganicAmmoniumNitrateChloride
J. Bottenheim, S. Netcheva – Environment Canada
ASCOS WorkshopLandskronaApril 9, 2008
Halogen Chemistry withOut On The Ice (OOTI)
Introduction
Spring time chemistryBr2 + hν → 2Br2(Br + O3 → BrO + O2) (O3 depletion)
BrO + DMS DMSOBr/BrO + Hg0 RGM mercury deposition
Question:Can this chemistry occur in the summer?
Instrumentation for Target Species
BrO: Multi-Axis Differential Optical Absorption Spectrometer (MaxDOAS, Ocean Optics)
O3: UV Absorption Based Monitor (2B)
Hg0: Atomic Absorption Mercury Vapour Analyzer (Gardis)