Analytical Ion Spectroscopy
Combining the individual analytical strengths of mass spectrometry and infrared spectroscopy, infrared ion spectroscopy is increasingly recognized as a powerful tool for small-molecule identification in a wide range of analytical applications.
Mass spectrometry is itself a leading analytical technique for small-molecule identification on the merit of its outstanding sensitivity, selectivity and versatility. The foremost shortcoming of the technique, however, is its limited ability to directly probe molecular structure, especially when contrasted against spectroscopic techniques.
In infrared ion spectroscopy (IRIS), infrared vibrational spectra are recorded for mass-isolated ions and provide a signature that can be matched to reference spectra, either measured from standards or predicted using quantum-chemical calculations.
As an example, researchers at FELIX have shown that it is possible to differentiate enantiomeric N-acetylhexosamines directly from body fluids using infrared ion spectroscopy, providing orthogonal identification of molecular structure unavailable by standard liquid chromatography/high-resolution tandem mass spectrometry. These results illustrate the potential for ion spectroscopy to be used for the identification of new functional biomarkers (in this care corresponding to an inborn error of metabolism), and more generally, for the identification of small molecules from complex mixtures.
Recently, we identified new biomarkers for pyridoxine-dependent epilepsy which resulted in a publication in The Journal of Clinical Investigations.
Promising new route
High-performance liquid chromatography mass spectrometry (HPLC/MS) is a widely used analytical technique. FELIX researchers have for the first time used HPLC/MS in combination with infrared ion spectroscopy. We have identified positional isomers of hydroxy-atorvastatins, active metabolites of the drug atorvastatin. In combination with chromatographic separation, infrared spectroscopy of mass-selected ions provides a promising new route for the identification of the molecular structures of unknown m/z peaks in complex mixture analysis. Using currently existing experimental protocols an IR spectrum can routinely be measured from only a few nanograms of sample.
- Infrared ion spectroscopy: New opportunities for small-molecule identification in mass spectrometry - A tutorial perspective.
J. Martens, R.E. van Outersterp, R.J. Vreeken, F. Cuyckens, K.L.M. Coene, U.F. Engelke, L.A.J. Kluijtmans, R.A. Wevers, L.M.C. Buydens, B. Redlich, G. Berden and J. Oomens
Analytica Chimica Acta 1093 (2020) 1-15.
© 2021 Elsevier. Analytica Chimica Acta (2020)
- Identification of organic micro-pollutants in surface water using MS-based infrared ion spectroscopy.
K.J. Houthuijs, M. Horn, D. Vughs, J. Martens, A.M. Brunner, J. Oomens, and G. Berden
Chemosphere 341 (2023) 140046.
© 2023 Elsevier. Chemosphere (2023)
- Evaluation of table-top lasers for routine infrared ion spectroscopy in the analytical laboratory.
R.E. van Outersterp, J. Martens, A. Peremans, L. Lamard, F. Cuyckes, J. Oomens, and G. Berden
Analyst 146 (2021) 7218-7229.
© 2021 Royal Society of Chemistry. Analyst (2021)
- Isomer-Specific Two-Color Double-Resonance IR2MS3 Ion Spectroscopy Using a Single Laser: Application in the Identification of Novel Psychoactive Substances.
F.A.M.G. van Geenen, R.F. Kranenburg, A.C. van Asten, J. Martens, J. Oomens, and G. Berden
Analytical Chemistry 93 (2021) 2687-2693.
© 2021 American Chemical Society. Analytical Chemistry (2021)
- Molecular identification in metabolomics using infrared ion spectroscopy.
J. Martens, G. Berden, R.E. van Outersterp, L.A.J. Kluijtmans, U.F. Engelke, C.D.M. van Karnebeek, R.A. Wevers, and J. Oomens
Scientific Reports 7 (2017) 3363.
© 2017 Nature Group. Scientific Reports (2017)
- Unraveling the unknown areas of the human metabolome: the role of infrared ion spectroscopy.
J. Martens, G. Berden, H. Bentlage, K.L. Coene, U.F. Engelke, D. Wishart, M. van Scherpenzeel, L.A.J. Kluijtmans, U.F. Engelke, C.D.M. van Karnebeek, R.A. Wevers, and J. Oomens
Journal of Inherited Metabolic Disease 41 (2018) 367–377.
© 2018 Springer. Journal of Inherited Metabolic Disease (2018)
- Combined Liquid Chromatography-Infrared Ion Spectroscopy for Identification of Regioisomeric Drug Metabolites.
J. Martens, V. Koppen, G. Berden, F. Cuyckens, and J. Oomens
Analytical Chemistry 89 (2017) 4359-4362.
© 2017 American Chemical Society. Analytical Chemistry (2017)
- Infrared Ion Spectroscopy of Environmental Organic Mixtures: Probing the Composition of α-Pinene Secondary Organic Aerosol.
E.Q. Walhout, S.E. Dorn, J. Martens, G. Berden, J. Oomens, P.H.-Y. Cheong, J.H. Kroll, R.E. O'Brien
Environmental Science and Technology 53 (2019) 7604-7612.
© 2019 American Chemical Society. Environmental Science and Technology (2019)
Other related articles
- Infrared ion spectroscopy in a modified quadrupole ion trap mass spectrometer at the FELIX free electron laser laboratory.
J. Martens, G. Berden, C.R. Gebhardt, and J. Oomens
Review of Scientific Instruments 88 (2016) 6126–6129.
© 2016 American Institute of Physics. Review of Scientific Instruments (2016)
- An automatic variable laser attenuator for IRMPD spectroscopy and analysis of power-dependence in fragmentation spectra.
G. Berden, M. Derksen, K.J. Houthuijs, J. Martens, and J. Oomens
International Journal of Mass Spectrometry 443 (2019) 1–8.
© 2019 Elsevier. International Journal of Mass Spectrometry (2019)
- Structural identification of electron transfer dissociation products in mass spectrometry using infrared ion spectroscopy.
J. Martens, J. Grzetic, G. Berden, and J. Oomens
Nature Communications 7 (2016) 11754.
© 2016 Springer Nature. Nature Communications (2016)
- Structures of Fluoranthene Reagent Anions Used in Electron Transfer Dissociation and Proton Transfer Reaction Tandem Mass Spectrometry.
J. Martens, G. Berden, and J. Oomens
Analytical Chemistry 88 (2016) 6126–6129.
© 2016 American Chemical Society. Analytical Chemistry (2016)