MAGNETIC-FIELD GRADIENTS IN NMR - FRIEND OR FOE

Anyone who has used an NMR spectrometer is familiar with magnetic fiel d gradients. In the form of inhomogeneities in the static field of the magnet they cause broadening of the spectral lines, often hindering a nalysis. Although this somewhat negative manifestation of the phenomen a is the first experience of most spectroscopists, a growing appreciat ion of their practical uses has resulted in some of the most important developments in NMR methodology over recent years, often extending it s uses far beyond its traditional role as an analytical tool for chemi sts. In this article we examine the place of magnetic field gradients in pulsed Fourier transform NMR from two perspectives: as a problem an d as a solution to problems.