A micropixelated ion-imaging detector for mass resolution enhancement of a QMS instrument


An in-vacuum position-sensitive micropixelated detector (Timepix) is used to investigate the time-dependent spatial distribution of different charge state (and hence different mass-to-charge (m/z)) ions exiting an electrospray ionization (ESI)-based quadrupole mass spectrometer (QMS) instrument. Ion images obtained from the Timepix detector provide a detailed insight into the positions of stable and unstable ions of the mass peak as they exit the QMS. With the help of image processing algorithms and by selecting areas on the ion images where more stable ions impact the detector, an improvement in mass resolution by a factor of 5 was obtained for certain operating conditions. Moreover, our experimental approach of mass resolution enhancement was confirmed by in-house-developed novel QMS instrument simulation software. Utilizing the imaging-based mass resolution enhancement approach, the software predicts instrument mass resolution of ∼1,0000 for a single-filter QMS instrument with a 210-mm long mass filter and a low operating frequency (880 kHz) of the radio frequency (RF) voltage.

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This work is part of the research program of the Foundation for Fundamental Research on Matter (FOM), which is part of the Netherlands Organisation for Scientific Research (NWO). The research is supported by the Comprehensive Analytical Science and Technology (COAST) foundation, which is the assigned program committee in the NWO Technology Area for Sustainable Chemistry (TASC) program. The authors acknowledge Ronald Buijs and Marc Duursma, of AMOLF for their contribution to the experiments.

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Correspondence to Ron M. A. Heeren.

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Published in the topical collection Mass Spectrometry Imaging with guest editors Andreas Römpp and Uwe Karst.

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Syed, S.U.A.H., Eijkel, G.B., Maher, S. et al. A micropixelated ion-imaging detector for mass resolution enhancement of a QMS instrument. Anal Bioanal Chem 407, 2055–2062 (2015). https://doi.org/10.1007/s00216-014-8158-0

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  • Mass spectrometry
  • Imaging
  • Spectroscopy/instrumentation