Pesticide mobility studied by nuclear magnetic resonance

Abstract

The adsorption-desorption mechanisms at the interface between organic and inorganic soil colloids influence the movement of pesticides, and in turn their bioavailability. Here we demonstrate the potential of high resolution magic angle spinning nuclear magnetic resonance (1H HR-MAS) to assess insitu interactions of pesticides at the solid aqueous interface. We used layered double hydroxides (LDH) also called anionic clays, due to their environmental relevance as soil models and cleaner materials for decontamination processes. We studied the adsorption behaviour of the pesticide 4-chloro-2-methylphenoxyacetic acid (MCPA) on anionic MgAl-clays. Our findings demonstrate that the mobile and immobile fractions of the pesticide can be unambiguously distinguished by 1H high resolution magical angle spinning nuclear magnetic resonance (1H-HR-MAS-NMR). © 2005 Springer-Verlag Berlin Heidelberg.