In-Situ Messung von organischen
Verbindungen in Aerosolen und in
der Luft am Hohen Sonnblick
Rupert Holzinger, Institute for marine and
atmospheric research (IMAU), Utrecht University.
IPCC, TAR:
POA: 138 Tg/yr
SOA: 17 Tg/yr
Kanakidou et al. 2005:
SOA: 36 Tg/yr
Goldstein and Galbally,
2007:
SOA: 510-910 Tg/yr
The basis: Proton-TransferReaction Mass-Spectrometry
(PTR-MS)
Soft ionization, low
fragmentation
High sensitivity
Most organic species can
be measured.
Quantitative for
uncalibrated compounds.
New approach: use PTR-MS for aerosols
Schematic of the new instrument
Key advantages of the new instrument:
Good time resolution and chemical
characterization.
Combined analysis of gas phase particulate
chemical composition.
High sensitivity (10 pg m-3) .
Gas phase/particle partitioning.
Capability to measure on semivolatile
compounds.
Comprehensive analysis of the totality of
organics in air.
Proton-Transfer-Reaction Mass-Spectrometry
Resolves fractional mass
difference of 37 mDa
between CH4 and O
components.
C7H11O+
C6H7O2+
C8H15+
200 C
time
150 C
100 C
50 C
109
110
111
112
mass spectrum
113
114
115
A full spectrum:
mass 60 – mass 100:
mass 100 – mass 150:
mass 150 – mass 200:
mass 200 – mass 250:
mass 250 – mass 300:
mass 300 – mass 350:
mass 350 – mass 400:
The instrument cycle:
All Masses detected:
Yellow: <10% of measurements above detection limit
Red: <50% of measurements above detection limit
0.4368
0.3276
fractional mass deviation [Da]
0.2184
0.1092
0
-0.1092
-0.2184
-0.3276
-0.4368
18
28
38
48
58
68
78
88
98
108 118 128 138 148 158 168 178 188 198 208 218 228 238 248 258 268 278 288 298 308 318 328 338 348 358 368 378 388 398 408 418 428
nominal mass [Da]
Detection limit: Median + 3 times standard deviation of background measurements
Oxygenated compounds :
0.2184
0.182
fracttional mass deviation [Da]
0.1456
0.1092
0.0728
0.0364
0
-0.0364
-0.0728
-0.1092
83
85
87
89
91
93
95
97
99
101
nominal mass [Da]
Mass CH4:
Mass O:
∆m:
16.031
15.995
36.4 mDa
103
105
107
109
111
113
115
117
Diurnal cycle
Time rowsTotal Organics
14000
Inlet A
12000
Inlet B
sum241 [ng/m3]
10000
8000
6000
4000
2000
0
0
6
12
18
24
time of day
aerosol concentration
14000
sum241 [ng/m3]
12000
10000
Inlet B
Inlet A
8000
6000
4000
2000
0
10-Jul
20-Jul
30-Jul
9-Aug
19-Aug
29-Aug
Time rows- the lowest concentrations
aerosol compounds
1
concentration [ng/m3]
0.9
m46.0648
m60.0226
m80.0424
m96.9621
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
10-Jul
20-Jul
30-Jul
9-Aug
19-Aug
29-Aug
Aerosol compounds @ 200C
3
2.5
m111.046
m111.081
m113.026
m113.060
m113.097
m115.040
nmo/m3
2
1.5
1
0.5
0
10-Jul
20-Jul
30-Jul
9-Aug
19-Aug
29-Aug
Globalstrahlung
Temperatur
1200.0
12.0
10.0
1000.0
6.0
800.0
4.0
600.0
2.0
400.0
0.0
-2.0
200.0
-4.0
0.0
10-Jul
-6.0
20-Jul
30-Jul
9-Aug
19-Aug
29-Aug
Temp [C]
Strahlung [W/m2]
8.0
Aerosol compounds @ 200C
3
2.5
m111.046
m111.081
m113.026
m113.060
m113.097
m115.040
nmo/m3
2
1.5
1
0.5
0
10-Jul
20-Jul
30-Jul
9-Aug
19-Aug
29-Aug
19-Aug
29-Aug
gasphase acetone
14
VMR [nmol/mol]
12
10
8
6
4
2
0
10-Jul
20-Jul
30-Jul
9-Aug
4
Aerosol compounds @ 150C
3.5
nmol/m3
3
2.5
150 C
m111.046
m111.081
m113.026
m113.060
m113.097
m115.040
2
1.5
1
0.5
4
Aerosol compounds @ 200C
3.50
10-Jul
20-Jul
30-Jul
9-Aug
19-Aug
29-Aug
nmo/m3
3
2.5
2
m111.046
m111.081
200 C
m113.026
m113.060
1.5
m113.097
m115.040
1
0.5
4.0
0
10-Jul
3.5
nmol/m3
3.0
20-Jul
Aerosol compounds @ 250C
30-Jul
9-Aug
19-Aug
29-Aug
250 C
2.5
m111.046
m111.081
m113.026
m113.060
m113.097
m115.040
2.0
1.5
1.0
0.5
0.0
10-Jul
20-Jul
30-Jul
9-Aug
19-Aug
29-Aug
Future work – in depth analysis:
Aerosol ageing/chemistry:
Thermograms
Degree of oxygenation
Cloud processing
Source regions/strengths:
Marker compounds?
Trajectory analysis
Interaction with gasphase:
Diurnal cycle
Partitioning