Phosphorus-31 nuclear magnetic resonance
Appearance
31P has an isotopic abundance of 100 %, and a spin state of 1/2, making it NMR active. Due to the 2nI+1 rule, the phosphorus spectrum tends to be quite simple. That phosphorus is commonly found in organic compounds and coordination complexes (as phosphines), making it useful to measure 31P NMR spectra routinely.
85 % phosphoric acid is commonly used as a standard.