NMR spectroscopy: a tool to study interactions between organic pollutants and soil components?

This paper reports studies from selected recent papers using NMR to investigate interactions between organic pollutants and soil matrices including SOM fractions, clays, whole soils or sediments, three main approaches are presented. First, an indirect approach consists to measure organic carbon normalized sorption coefficients (K

oc

values) of organic pollutants with soil matrices and then to establish correlations between these values and structural elements of soil organic matter (carboxylic, carbonyl, aromatic, aliphatic groups⋯). In that case, NMR technique only plays a role in determining soil organic matter structure. Second are reported solid state NMR (

13

C and

15

N CP-MAS, cross polarization magic angle spinning) experiments which are the main tools to investigate covalent bonds between organic pollutants and SOM. Finally are described experiments carried out on hydrated solid matrices using HR-MAS (high resolution magic angle spinning) NMR. This approach, which is the most recent and novel, allows characterizing molecular species at the solid-aqueous interface, these species are differentiated according to their degree of mobility. It should help to investigate the major question of bio-availability of organic pollutants, mainly for bacteria.