Determination of the Identity, Content and Purity of Therapeutic Peptides by NMR Spectroscopy
This chapter describes the application of NMR spectroscopy to the determination of the identity, content, structure and purity of peptides. Both 1D and 2D NMR examples are presented for both 1H and other nuclei. NMR spectroscopy is a nondestructive technique requiring limited sample pretreatment and development time. The limited sample pretreatment reduces the experimental time and variations due to handling, thereby increasing robustness. NMR spectroscopy can distinguish between very closely related peptides. It is especially suited for the determination of unrelated impurities such as process-related impurities and extractables/leachables. NMR spectroscopy is very sensitive to higher-order structure. Although NMR equipment in itself is expensive, the actual cost of an NMR spectrum is low owing to automation and limited consumables.