Derivatization of compounds containing -OH groups can be accomplished quantitatively with 1,3,2-dioxaphospholanyl chloride. The chemical shifts of phosphorus in the derivatives clearly differentiate alcohols from phenols and carboxylic acids. Quantitation is obtained by use of 31P FT-NMR spectroscopy in the presence of 2,2,6,6-tetrameth-ylpiperidinyloxy free radical to shorten relaxation times. Compounds with phosphorus chemical shifts differing by as little as 0.1 ppm can be separately determined.
David E. Schiff, John G. Verkade, Robert M. Metzler, Thomas G. Squires, and Clifford G. Venier, "Determination of Alcohols, Phenols, and Carboxylic Acids Using Phosphorus-31 NMR Spectroscopy," Appl. Spectrosc. 40, 348-351 (1986)