ASCOS Pre-Expedition Workshop
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ASCOS Pre-Expedition Workshop Contributing Efforts to ASCOS using the Proton Transfer Reaction Technique for VOC Analysis M. Müller, M. Graus, A. Wisthaler, A. Hansel Institute of Ion Physics and Applied Physics, University of Innsbruck, Austria
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Contributing Efforts to ASCOS using the Proton Transfer Reaction Technique for VOC Analysis. M. Müller , M. Graus, A. Wisthaler , A. Hansel Institute of Ion Physics and Applied Physics, University of Innsbruck , Austria. ASCOS Pre-Expedition Workshop. PTR-MS:. - PowerPoint PPT Presentation
Transcript of ASCOS Pre-Expedition Workshop
ASCOS Pre-Expedition Workshop
Contributing Efforts to ASCOS using the Proton Transfer
Reaction Technique for VOC Analysis
M. Müller, M. Graus, A. Wisthaler, A. Hansel Institute of Ion Physics and Applied Physics, University of Innsbruck, Austria
ASCOS Pre-Expedition Workshop
PTR-MS:
H2O
H2O+
O+
H+
OH+
H3O+
H3O+ H3O+ H3O+
VOC
VOC•H+e–
H3O+
H3O+
H3O+
Proton transfer reaction when
PA(VOC)>PA(H2O)
Reaction: H3O+ + VOC → VOCH+ + H2O
• Most hydro carbons and derivates Terpenes Aromatics
• Photo oxidation products and other oxyVOCs Ketones Aldehydes Alcohols
• Aerosol precursors DMS and oxidation products (DMSO) High molecular species (semi volatile)
What do we detect:
ASCOS Pre-Expedition Workshop
Advantages:• Compact organic trace gas analyser• Mostly non dissociative ionization• Excellent sensitivity• Low limit of detection ~10 pptv
Performance Summary PTR-MS:
Disadvantage:• Poor selectivity
ASCOS Pre-Expedition Workshop
ASCOS Pre-Expedition Workshop
M. Graus, M. Müller, A. Wisthaler, A. Hansel
Time of Flight
Sign
al
PTR Drift Tube TOF-MS
Pulser Detector
Sample Inlet
Acquisition
Timing
HR PTR-TOFMS:
ASCOS Pre-Expedition Workshop
Performance Summary HR PTR-TOFMS:
• Detects all ions in one instant• Separation of isobars is possible• Identification of the elemental composition• High sensitivity• Low pptv range LOD
m/z=79.022m/z=79.055
Planed Innsbruck’s contributions to ASCOS:
Analysis of solved VOCs in sea water: •Surface µ-layer samples•Surface layer samples
Heli profiles of VOCs
VOC air mass characterization
Aerosol collection (5 stage BCI) and analysis for organic compounds
Continuous measurements
6-8 SilcoCan off-line sampling
technique
HLC-Setup•Molekular mass
•HLC for identification•quantitativ
Off-line thermal desorption
analysis
EGU General Assembly 2008
Why off-line heli profiles using 6-8 SilcoCans?
Lets look at some AOE 2001 data!
EGU General Assembly 2008
AOE Results by Armin Wisthaler:
Expected SilcoCan Data
EGU General Assembly 2008
AOE Results by Armin Wisthaler:
Expected SilcoCan Data
Very low DMS concentration => high signal/noise
High precision datalow signal/noiseWhole mass scans possibleIsobaric identification possible (TOF)
EGU General Assembly 2008
THANK YOU
