Zero-field NMR enhanced by parahydrogen in reversible exchange

J Am Chem Soc. 2012 Mar 7;134(9):3987-90. doi: 10.1021/ja2112405. Epub 2012 Feb 22.


We have recently demonstrated that sensitive and chemically specific NMR spectra can be recorded in the absence of a magnetic field using hydrogenative parahydrogen induced polarization (PHIP) (1-3) and detection with an optical atomic magnetometer. Here, we show that non-hydrogenative parahydrogen-induced polarization (4-6) (NH-PHIP) can also dramatically enhance the sensitivity of zero-field NMR. We demonstrate the detection of pyridine, at concentrations as low as 6 mM in a sample volume of 250 μL, with sufficient sensitivity to resolve all identifying spectral features, as supported by numerical simulations. Because the NH-PHIP mechanism is nonreactive, operates in situ, and eliminates the need for a prepolarizing magnet, its combination with optical atomic magnetometry will greatly broaden the analytical capabilities of zero-field and low-field NMR.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Hydrogen / chemistry*
  • Magnetic Resonance Spectroscopy
  • Pyridines / analysis


  • Pyridines
  • Hydrogen
  • pyridine