This work undertakes the study of the detoxification reactions of O, S-dimethyl phosphoramidithioate (methamidophos) as an organophophorus insecticide on the 14.7 wt% magnetite (Fe3O4) nanoparticles/Ag-NaY faujasite molecular sieve zeolite (FMSZ) composite. The influence of solvent (methanol, acetonitrile and n-hexane) on the detoxification potential of composite was investigated. For this survey, in the first step, sodium type-Y (NaY) zeolite was synthesized by hydrothermal method (HM). Then, Ag-NaY zeolite was prepared from NaY zeolite by ion-exchange method (IEM). In the next step, Fe3O4 nanoparticles (NPs) were incorporation and deposited on the Ag-NaY zeolite structure by using precipitation method (PM). The synthesized samples were characterized by SEM, EDAX and XRD techniques. The GC-FID and IR analyses results demonstrated that about 99% of methamidophos was detoxified (adsorbed) via this composite at n-hexane solvent after 10 h. On the other hand, the results for the acetonitrile and methanol solvents were lower. It seems that a nonpolar solvent transfer to the reactive surface site on the composite without occupying and blocking of these sites.