P-31 MAS NMR-STUDY OF THE HYDROLYSIS OF O,S-DIETHYL PHENYLPHOSPHONOTHIOATE ON REACTIVE SORBENTS

P-31 MAS NMR was used to monitor the hydrolysis of O,S-diethyl phenylphosphonothioate (DEPPT) sorbed on gamma-alumina, XE-555 (a mixture of strong-acid/strong-base ion exchange resins and a carbonaceous adsorbent), and a polydivinyl-benzene sorbent impregnated with NaOH. The products were identified to determine the amount of P-O/P-S bond hydrolysis occurring on the sorbents. The relative order of reactivity observed for the sorbents is: polydivinylbenzene/NaOH > gamma-alumina >> XE-555. Distinct P-31 MAS NMR peaks were observed for DEPPT sorbed on the individual components of XE-555. P-31 MAS NMR also suggested the presence of mobile and translationally-restricted phases for DEPPT sorbed on gamma-alumina. These aspects of DEPPT sorption provided by P-31 MAS NMR enabled a better understanding of the DEPPT reactivity observed on XE-555 and gamma-alumina.