phosphorus-radioisotopes and edifenphos

Movement and Metabolism of 32P and 35S-double labeled Kitazin P (S-benzyl O,O-diisopropyl phosphorothiolate) and 35S-labeled edifenphos (O-ethyl S,S-diphenyl phosphorodithiolate) were examined with three types of soils, sandy loam, alluvial clay loam, and volcanic ash loam. Vertical movement of both the compounds in soil column was different with soil types, and the order of mobility in soil column was as follows: sandy loam greater than alluvial clay loam greater than volcanic ash loam. Persistence of edifenphos in soil was shorter than that of Kitazin P. Main degradation products at the initial stage of metabolism were S,S,S-triphenyl phosphorotrithiolate, O,O-diethyl S-phenyl phosphorothiolate, S-phenyl dihydrogen phosphorothiolate and diphenyl disulfide in edifenphos and O,O-diisopropyl hydorgen phosphorothioate in Kitazin P. Sulfur atom of Kitazin P was found in sulfuric acid at a minor level through dibenzyl disulfide and toluene-alpha-sulfonic acid, and that of edifenphos was converted to sulfuric acid through diphenyl disulfide and benzenesulfonic acid. Kitazin P under flooded condition of alluvial clay loam was slightly more persistent as compared with upland condition. Sterilized condition of Kitazin P did not cause any appreciable degradation throughout the experimental period, but such condition did not necessarily prevent the degradation of edifenphos.

Topics: Biodegradation, Environmental; Chromatography, Ion Exchange; Fungicides, Industrial; Organothiophosphorus Compounds; Phosphorus Radioisotopes; Soil; Solubility; Sulfur Radioisotopes; Time Factors