Dresden 2011 – scientific programme

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MO: Fachverband Molekülphysik

MO 26: Poster: Biomolecules

MO 26.5: Poster

Thursday, March 17, 2011, 16:00–18:00, P2

Combining an Ion Mobility Spectrometer with IR spectroscopy — •Stephan Warnke, Gerard Meijer, and Gert von Helden — Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany

The shape and three-dimensional structure of large molecules or clusters in the gas phase is of interest but difficult to investigate. While in the condensed phase various structure-resolving methods exist, methods applicable to gas phase molecules are limited. Two structure-sensitive methods are IR spectroscopy and ion mobility spectrometry (IMS). In IMS, molecules are ionized and they subsequently drift through a buffer gas under the influence of an electric field. Species with different collisional cross sections are separated after many collisions with the buffer gas molecules. By measuring the drift time of each species, information about its structure can be obtained. The combination of IMS with IR spectroscopy therefore yields complementary information as IR spectroscopy is sensitive to the local environment while IMS is more sensitive to the global structure.

We are in the process of building a machine consisting of a nano-ESI source and a drift cell (i.e. the IMS part) prior to a quadrupole mass spectrometer and an ion trap with optical access for spectroscopy on conformer and mass/charge selected ions. The design of the ion mobility spectrometer and first experimental results will be presented.