Dissolved organic matter is a highly complex mixture and deciphering its molecular-level composition represents an analytical challenge. Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS) coupled to electrospray ionization is a valuable tool which can resolve the exact masses of intact molecules. We operate a Bruker Solarix XR with a 15 Tesla magnet. Electrospray Ionization (ESI) or Atmospheric Pressure Chemical Ionization (APCI) sources are available to ionize nonpolar to very polar compounds. The dynamically harmonized ParaCell allows the acquisition of spectra at extreme resolution (R>10,000,000).  For routine analyses of large sample sets, a CTC PAL 3 autosampler can be connected to the instrument. Continuous method development and data evaluation routines for molecular formula assignment to the thousands of peaks detected per spectrum are core tasks within the working group.


  • Dissolved organic matter molecular composition from marine or freshwater environments or laboratory experiments
  • Characterization of oils and asphaltenes
  • MS-MS experiments to characterize core structures
  • Natural products characterization


Selected publications:

Zark, M, Christoffers J and Dittmar T (2017). Molecular properties of deep-sea dissolved organic matter are predictable by the central limit theorem: evidence from tandem FT-ICR-MS. Marine Chemistry 191, 9-15.

Waska H, Koschinsky A and Dittmar T (2016) Fe- and Cu-complex formation with artificial ligands investigated by ultra-high resolution Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS): Implications for natural metal-organic complex studies. Frontiers in Marine Science 3:1-19.

Pohlabeln A and Dittmar T (2015) Novel insights into the molecular structure of non-volatile marine dissolved organic sulfur. Marine Chemistry 168, 86-94.

Dittmar T and Paeng J (2009) A heat-induced molecular signature in marine dissolved organic matter. Nature Geoscience 2, 175-179.

Koch BP, Dittmar T, Witt M and Kattner G (2007) Fundamentals of molecular formula assignment to ultrahigh resolution mass data of natural organic matter. Analytical Chemistry 79, 1758-1763.


Katrin Klaproth
Campus Wechloy
(+49) 441 - 798 3773

(Changed: 2021-04-30)