The Role of Pulsed-field Gradients in Modern NMR Pulse Sequence Design

Abstract

Pulsed-field gradients (PFGs) play an important role in the development and understanding of modern NMR methods. With the ultimate goal of constructing robust pulse sequences that create high-quality NMR spectra with minimum set-up, PFGs are utilized to achieve an exclusive selection of a specific coherence transfer pathway as well as to purge all kinds of undesired magnetization. PFGs reduce the number of needed phase cycle steps to a bare minimum, allowing for accelerated NMR data acquisition in shorter spectrometer times. The potential and diversity of several PFG-based NMR elements are presented, as well as instances of their implementation in time-efficient NMR solutions. Practical aspects such as NMR data collection needs and the attainment of pure in-phase absorption lineshapes are discussed for the most useful NMR experiments.