[LINK9]

Soil analysis – Various NMR active nuclei

³¹P NMR can be used to determine the organic/inorganic phosphorus in soils, water bodies and environmental samples more than any other technique. Origin of environmental samples includes agricultural, forest, natural ecosystem, humic acid, manure, compost, sludge, fresh water, estuary, marine water, municipal solid waste, fertilizers, etc. Similar strategy can be adopted with solid-state ¹⁵N and ¹³C NMR analysis for the study of organic/inorganic phases involving nitrogen and carbon based species.

The ³¹P NMR signals of phosphorous compounds of interest generally fall between 30 and -30 ppm. These include; phosphonates at around 20 ppm, orthophosphate at 6.2 ppm, orthophosphate monoesters at 4-7 ppm, orthophosphate diesters, including phospholipids and DNA at 3 to -4 ppm, pyrophosphate at -4 to -6 ppm, and polyphosphate at around -20 ppm.