Application of P-31 NMR spectroscopy in food analysis. 1. Quantitative determination of the mono- and diglyceride composition of olive oils

This paper introduces a facile method to determine the amount of mono- and diglycerides in virgin olive oils. This method is based on the phosphorylation of the free hydroxyls of the mono- and diglycerides with 2-chloro-4,4,5,5-tetramethyldioxaphospholane and the integration of the appropriate peaks in the P-31 NMR spectrum. Quantitative P-31 NMR spectroscopy can be extended to the quantification of other constituents of olive oils bearing functional groups with labile protons.