A method and apparatus for ex-situ nuclear megnetic resonance spectroscopy for use on samples outside the physical limits of the magnets in inhomogeneous static and radio-frequency fields. Chemical shift spectra can be resolved with the method using sequences of correlated, composite z-rotation pulses in the presence of spatially matched static and radio-frequency field gradients producing nutation echoes. The amplitude of the echoes id modulated by the chemical shift interaction andd an inhomogeneity free FID may be recovered by stroboscopically sampling the maxima of the echoes.
METHOD AND APPARATUS FOR HIGH RESOLUTION EX-SITU NMR SPECTROSCOPY