NMR: New techiques for chemical analysis and biological investigation

Nuclear magnetic resonance (NMR) has become an increasingly valuable technique over the last three decades for the study of molecular structure of organic compounds. Within recent years a number of major advances in experimental methods have led to an explosion in the information elicited from NMR spectra and to a spectacular increase in the kinds of samples that can be studied by NMR. With the use of higher magnetic fields and greatly improved electronic techniques, NMR has undergone orders of magnitude increase in sensitivity, so that low concentrations of materials can be studied in chemical samples and in living systems, from cells to whole animals and humans. The use of two-dimensional NMR methods permits the unravelling of complex spectra, and innovative pulse techniques provide high resolution NMR spectra in solids. NMR imaging furnishes information on spatial distribution of materials and permits discrimination among various kinds of tissues. This chapter reviews some fundamentals of NMR and presents an elementary account of the theory and methods used in modern NMR applications.