New applications, processing methods and pulse sequences using diffusion NMR

Diffusion NMR, and in particular the DOSY processing method (Diffusion Ordered SpectroscopY), is an attractive technique to characterize mixtures without first having to separate the components. As a result, DOSY can yield a vast amount of analytical information. General applications of DOSY are reviewed here although we emphasize specialist applications that provide unique data. Such applications include the analysis of kinetic products, the detection of impurities in complex mixtures and the analysis of foodstuffs. We also focus on recent applications, such as the incorporation of DOSY into drug discovery protocols and as a filter in the analysis of natural product extracts or compound libraries. Depending on the characteristics of the sample under study, a careful choice of DOSY NMR experiment and its processing strategy is required to obtain optimum results. Moreover, this review describes the strengths and weakness of the different DOSY experimental and processing methods from the perspective of its application by the analytical chemist to a larger variety of sample types.