Electrospray Ionization Fourier Transform Ion Cyclotron Resonance at 9.4 T

Authors

  • Michael W. Senko,

    1. Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, 1800 E. Paul Dirac Drive, Florida State University, Tallahassee, FL 32310 USA
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  • Christopher L. Hendrickson,

    1. Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, 1800 E. Paul Dirac Drive, Florida State University, Tallahassee, FL 32310 USA
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  • Ljiljana Paša-Tolić,

    1. Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, 1800 E. Paul Dirac Drive, Florida State University, Tallahassee, FL 32310 USA
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  • Jarrod A. Marto,

    1. Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, 1800 E. Paul Dirac Drive, Florida State University, Tallahassee, FL 32310 USA
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  • Forest M. White,

    1. Department of Chemistry, Florida State University, Tallahassee, FL 32310 USA
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  • Shenheng Guan,

    1. Department of Chemistry, Florida State University, Tallahassee, FL 32310 USA
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  • Alan G. Marshall

    Corresponding author
    1. Department of Chemistry, Florida State University, Tallahassee, FL 32310 USA
    • Department of Chemistry, Florida State University, Tallahassee, FL 32310 USA
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Abstract

We present the first results from a new electrospray ionization Fourier transform ion cyclotron resonance mass spectrometer operated at a magnetic field of 9.4 T (i.e. ⩾2.4 T higher than for any prior FTICR instrument). The 9.4 T instrument provides substantially improved performance for large molecules (⩾50% increase in mass resolving power) and complex mixtures (⩾100% increase in dynamic range) compared to lower-field (⩽6 T) instruments. The higher magnetic field makes possible larger trapped-ion population without introduction of significant space–charge effects such as spectral peak shift and/or distortion, and coalescence of closely-spaced resonances. For bovine ubiquitin (8.6 kDa) we obsrve accurate relative isotopic abundances at a signal-to-noise ratio greater than 1000:1, whereas a complete nozzle-skimmer dissociation electrospray ionization (ESI) FTICR mass spectrum of bovine carbonic anhydrase (29 kDa) is achieved from a single scan with a signal-to-noise ratio of more than 250:1. Finally, we are able to obtain mass resolving power, m/Δm>200 000, routinely for porcine serum albumin (67 kDa). The present performance guides further modifications of the instrument, which should lead to significant further improvements.

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