748003 VU Applications of Chemical Ionisation Mass Spectrometry to Trace Gas Analysis

Wintersemester 2024/2025 | Stand: 17.10.2024 LV auf Merkliste setzen
748003
VU Applications of Chemical Ionisation Mass Spectrometry to Trace Gas Analysis
VU 4
5
wöch.
semestral
Englisch
  • To introduce state-of-the-art soft chemical ionisation mass spectrometric (SCIMS) techniques, namely; Proton Transfer Reaction – Time-of-Flight – Mass Spectrometry (PTR-ToF-MS), Selected Ion Flow Tube – Mass Spectrometry (SIFT-MS) and Ion Mobility Spectrometry (IMS)
  • Compare SCIMS to more standard mass spectrometric analytical techniques including the “gold-standard” of analytical chemistry; namely Gas Chromatography – Mass Spectrometry (GC-MS) – advantages and disadvantages
  • To provide a framework for gaining a knowledge and an understanding on the use of reagent ions as sensitive and selective analytical probes for use in many areas of analytical chemistry – interdisciplinary and intersectoral perspectives
  • Comparison of SCIMS to more standard mass spectrometric analytical techniques including the “gold-standard” of analytical chemistry; namely Gas Chromatography – Mass Spectrometry (GC-MS) – advantages and disadvantages
  • To provide a major practical hands-on research project within the Institute for Breath Research using state-of-the-art PTR-MS instruments – students will become proficient in using PTR-MS and in the analysis of the mass spectrometric data obtained:
    - putting the context of the lectures into real-world applications
    - gaining experience of working in a research environment (team and independent work)
    - gaining skills in the use of using state-of-the-art soft chemical ionisation mass spectrometric and analysis techniques (An Ionicon Analytik GmbH PTR-TOF 6000 X2)
    - developing experimental, critical thinking and analytical skills
    - gaining experience in writing and presenting scientific reports

1. Lecture Material
Analytical performance of a SCIMS instrument-Ions as Sensitive Analytical Probes to the Environment

Accuracy and precision, Sensitivity, Limits of detection, Mass accuracy, Selectivity, Use of ion-molecule reaction rate coefficients to determine compound concentration

Principles of Proton Transfer Reaction Mass Spectrometry

Non-dissociative and dissociative proton transfer, Operational principles, Soft ionisation versus electron impact ionisation, Determining concentrations, Selectivity

Proton Transfer Reaction Mass Spectrometry and the Reduced Electric Field

Residence times, Mean drift velocities, Collisional energies (Wannier equation) and effective temperatures, Sensitivity, Limits of detection

Proton Transfer Reaction Mass Spectrometry: Improving Selectivity and Response Time

Selectivity of PTR-MS – methods employed to improve selectivity, Response Time of Measurements with PTR-MS – changing reagent ions, Latest PTR-MS developments

Selected Ion Flow Tube Mass Spectrometry (SIFT-MS)

Operational principles, Determining absolute rate coefficients, Use in trace gas analysis – commercialisation of SIFT-MS, Advantages and disadvantages of SIFT-MS

Ion Mobility Spectrometry (IMS)–Principles and Methods

Operational principles, Mobility coefficient, Mean drift velocity, Reagent ion peak, IMS spectra, Ionisation sources, IMS-MS, Applications of IMS, Advantages and disadvantages of IMS

Ion Mobility Spectrometry (IMS)-Positive Ion Mode

Reagent ion formation, Applications (CWAs and Drugs)

Ion Mobility Spectrometry (IMS)-Negative Ion Mode

Reagent ion formation, Applications (Explosives), Electron attachment investigations – IMS and swarm measurements

IMS and Improved Selectivity

Dopants, GC-IMS, Collisional Induced Dissociation, High Kinetic Energy Ion Mobility Spectrometry

Soft Chemical Ionisation Mass Spectrometry and Atmospheric Chemistry

The biosphere, Plant studies and influences on the atmosphere, Chamber studies, Emission monitoring, Biomass burning, Airborne and shipborne measurements

Soft Chemical Ionisation Mass Spectrometry and Food Science

Mass spectral fingerprinting, Flavour release and perception, Food classification, Food freshness and ripening

Soft Chemical Ionisation Mass Spectrometry and Homeland Security

Thermal desorption PTR-MS, Explosive detection with PTR-MS

Soft Chemical Ionisation Mass Spectrometry and Health Sciences

Breath analysis, Urine analysis, Skin emanations, Endogenous verses exogenous volatile sources, PTR-MS and breath research, Volatiles and breath tests in clinical practice

Electronic Sensors–Future Directions

Chemical recognition by chemical gas sensors

2. Research Project (5 days)–Applications of PTR-MS to Breath Analysis
Extensive training on the operation of the state-of-the-art PTR-ToF-MS (an Ionicon Analytik GmbH PTR-TOF 6000 X2) and analyses of data.

Measure the breath concentrations (VMRs) of key volatiles in breath, Calculate the breath concentrations and compare to measured values, Investigate temporal changes of breath volatile concentrations (pharmacokinetics)

Lectures and Experimental Work (taught in English)

To provide a series of tutorial style lectures drawing together and developing concepts from various disciplines (e.g. chemistry, physics, and biosciences) and different subjects (e.g. quantum mechanics, plasma physics, statistical mechanics, and electromagnetism) to describe the applications of ion-molecule processes for use in gas-phase analytical chemistry. 

G.A. Eiceman, Z. Karpas, H. H. Hill „Ion Mobility Spectrometry” - ISBN: 9781138199484 
(CRC Press 2016)

A. M. Ellis and C. A. Mayhew “Proton Transfer Reaction Mass Spectrometry: Principles and Applications - ISBN: 978-1-4051-7668-2 (Wiley 2014)” 350 pages (provided)

VO Fundamentals of Chemical Ionisation Mass Spectrometry

07.10.2024
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748003-0 01.09.2024 00:00 - 31.01.2025 23:59 Zur LV anmelden