Ca’ Foscari University of Venezia 1 article published in JoVE Chemistry Quantitative 31P NMR Analysis of Lignins and Tannins Dimitris S. Argyropoulos2, Nicolò Pajer1, Claudia Crestini1 1Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venezia, 2Departments of Chemistry and Forest Biomaterials, North Carolina State University 31P NMR is a powerful tool for the structural elucidation of polyphenols. This fast, easy, precise, quantitative, and highly reproducible analytical procedure, that allows for the quantification and differentiation of the different types of hydroxy, phenolic, and carboxylic groups in lignins and tannins has now become a routine analytical tool.