A dynamic nuclear polarization strategy for multi-dimensional Earth's field NMR spectroscopy

Meghan E. Halse, Paul T. Callaghan

Research output: Contribution to journalArticlepeer-review


Dynamic nuclear polarization (DNP) is introduced as a powerful tool for polarization enhancement in multi-dimensional Earth's field NMR spectroscopy. Maximum polarization enhancements, relative to thermal equilibrium in the Earth's magnetic field, are calculated theoretically and compared to the more traditional prepolarization approach for NMR sensitivity enhancement at ultra-low fields. Signal enhancement factors on the order of 3000 are demonstrated experimentally using DNP with a nitroxide free radical, TEMPO, which contains an unpaired electron which is strongly coupled to a neighboring N nucleus via the hyperfine interaction. A high-quality 2D F-H COSY spectrum acquired in the Earth's magnetic field with DNP enhancement is presented and compared to simulation.
Original languageEnglish
Pages (from-to)162-168
Number of pages7
JournalJournal of Magnetic Resonance
Issue number2
Early online date17 Sept 2008
Publication statusPublished - Dec 2008


  • Earth's magnetic field
  • Dynamic nuclear polarization
  • Sensitivity enhancement
  • Multi-dimensional spectroscopy
  • Nuclear magnetic resonance

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