Stuttgart 2012 – scientific programme

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MO: Fachverband Molekülphysik

MO 5: Experimental Techniques

MO 5.7: Talk

Monday, March 12, 2012, 18:00–18:15, V38.02

A High Resolution Ion Mobility Spectrometer to preselect molecular conformers for gas-phase spectroscopy — •Stephan Warnke, Kevin Pagel, Gerard Meijer, and Gert von Helden — Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany

A key technique to investigate biomolecules in the gas phase is mass spectrometry and many methods are available to obtain mass/charge ratios with very high accuracy. However, with MS methods only little information on the higher order structure is obtained - even though their knowledge is crucial for the understanding of intra- and intermolecular interactions as well as the function of the molecule. Two techniques that are sensitive to the higher order structure of gas-phase molecules are ion mobility spectrometry (IMS) and infrared (IR) spectroscopy, of which both can be combined with mass spectrometry.

In IMS, the absolute (angle averaged) collision cross section and, thus, the effective size of the ion is determined. Additionally, when ions coexist in different conformations, they can be separated in space and time to allow for experiments on both mass/charge as well as (geometrical) shape/charge selected ions.

In this talk, the setup of our high resolution ion mobility spectrometer and first results on peptides and small proteins will be presented. In additon, strategies to utilize the existing instrument as a tool to conformationally pre-select biomolecules for gas-phase IR spectroscopy experiments will be discussed.