Local motions of organic pollutants in soil components, as studied by 2H NMR

H-2 NMR spectra and interpretations are presented on a series of samples, each consisting of a deuterium-labeled organic pollutant (trichloroethylene, acetone, pyridine; benzene, or ethylene glycol) adsorbed on a soil component (montmorillonite clay or humic acid). Spectra were obtained over a wide temperature range and using two values of the quadrupolar echo delay period. Computer simulations of line shapes resulting from various forms of local motion of C-H-2 moieties provide useful guidelines for interpreting the experimental results. In a few cases, detailed line shape simulations are given. This approach is attractive for elucidation of the detailed motional behaviors of organic pollutants adsorbed in soil.