Phosphorus-31 NMR spectroscopy is an analytical chemistry technique that uses nuclear magnetic resonance (NMR) to study chemical compounds that contain phosphorus. Phosphorus is commonly found in organic compounds and coordination complexes (as phosphines), making it useful to measure - NMR spectra routinely. Solution P-NMR is one of the more routine NMR techniques because P has an isotopic abundance of 100% and a relatively high gyromagnetic ratio. The P nucleus also has a spin of , making spectra relatively easy to interpret. The only other highly sensitive NMR-active nuclei spin  that are monoisotopic (or nearly so) are H and F.