Mass Spectrometry Group

 Mass spectrometry lab
zum Bild Mass spectrometry lab

Molecular Beam Mass Spectrometry (MBMS) is an analytical technique for determining the molecular weight of molecules sampled from a reactive environment. Gases are probed in-situ and the sample is expanded into a molecular beam. Thus chemical reactions are quenched immediately and the sample composition is "frozen". Even highly reactive species, such as radicals, are preserved by this sampling technique and are thus detectable.  The subsequent mass spectrometric analysis allows for the separation of species by their individual molecular weight.

The combination of molecular beam sampling with a time of flight mass spectrometer (TOF) provides multiple advantages:

  • Simultaneous detection of almost all species relevant to combustion
  • Detection of free radicals and other high reactive species
  • Detection of the entire mass range from the molecular gas phase up to particles in the nanometer range
  • High repetition rate: up to 40,000 mass spectra per second
  • Selective detection due to the use of photo ionization techniques

The group operates two mass spectrometers with different focus:

  1. A mobile Photo Ionization Mass Spectrometer (PIMS) optimized for detection of (nano) particulate matter
  2. High temperature flow reactor with MBMS detection for validation of gas phase reaction kinetics


Dr. rer. nat. Markus Köhler
German Aerospace Center

Institute of Combustion Technology

Tel: +49 711 6862-756

Fax: +49 711 6862-578

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