To obtain highly sensitive information on molecular structure and function, nuclear magnetic resonance (NMR) relies on a strong magnetic field. However, Alexander Pines at the University of California, Berkeley, and his co-workers have achieved high resolution and intense NMR spectra at zero magnetic field.
In conventional NMR, the external field partially aligns the nuclear spins in the molecule of interest. The authors’ technique uses a polarizing agent to do roughly the same thing. The agent, parahydrogen, reacts with the molecule, inducing a greater degree of polarization of nuclear spins than conventional NMR, thereby
enhancing the signal. The signals are then detected with a sensitive atomic magnetometer.
Using their technique, the authors were able to distinguish the structural features of several compounds. They say their method could be used as a low-cost, portable alternative to standard NMR machines. Nature Phys. doi:10.1038/nphys1986 (2011)