NMR Diffusion Experiments for Complex Systems

1. Introduction The last decade has seen a considerable increase in the number of biochemical and biomedical applications of PFG NMR diffusion methods. However, despite commercial availability of powerful, stable, and reproducible gradient units, 1 H diffusion measurements of low-concentration solutes in non-deuterated media can still present a challenging problem. Large solvent peaks can make integration of small solute peaks extremely difficult. Complex mixtures can also be difficult to work with, due to spectral crowding. At the same time, non-deuterated, spectrally crowded systems must routinely be dealt with in many of the practically relevant experimental situations, such as NMR of biofluids, proteins, or cellular systems. Our ongoing work in this area has been directed at the development of NMR diffusion experiments which deal with these problems by using contemporary solvent suppression and multiple-quantum filtering techniques.