Disulfoton (Di-Syston) [0,0-Diethyl S-(2-ethylthioethyl) phosphorodithioate ] 
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After intraperitoneal injection of labeled di-syston into rats, the 
rats were sacrificed and the livers analyzed. Di-syston sulfoxide, di- 
syston sulfone, di-syston-P=0 sulfoxide and di-syston-P=0 sulfone were 
found. In the urine collected from treated rats, only hydrolytic products 
were identified: diethyl phosphate, diethyl phosphorothioate, diethyl 
phosphorodithioate, and inorganic phosphate. Four other compounds were 
observed but not identified. The di-syston phosphorothiolate derivate 
was not found (197). 
Di-syston-P?* was injected into bollworm larvae which were sacri-~ 
ficed at varying intervals. Di-syston sulfoxide and sulfone, di=syston- 
P=0 sulfoxide and sulfone, inorganic phosphate, ethyl phosphate, diethyl 
phosphate, diethyl phosphorothiolate and several unidentified compounds 
were found. Examination of the excreta gave similar results. After 
exposure of tobacco budworms to labeled di-syston, the same products were 
found. However, the rate of metabolism of di-syston and its metabolites 
was greater (197). 
In vegetables, di-syston was first oxidized to P=0. Thereafter, the 
thio group was converted successively to -SO- and -SO»,- (1107). 
Cotton leaves and seedlings were treated with labeled di-syston. 
Initial oxidation of the 2-ethylthio ether was very rapid. After one 
day, di-syston sulfone was the major metabolite. After 16 days, the 
major metabolite was di-syston-P=0 sulfone. The only hydrolytic products 
found were inorganic phosphate, diethyl phosphate, and diethyl phosphoro- 
thioate (197). Similar results were obtained with lemon, bean, and alfalfa 
plants (992). Metabolites of di-syston on onions were identified as the P=0 
analog, the sulfone and sulfoxide (1107). 
Adsorption of disulfoton by soil was studied by a wet slurry 
technique. Extraction studies of soils and solutions after equilibration 
showed that some disulfoton was lost by microbial alteration and adsorption 
by glass. The empirical Freundlich isotherm fitted adsorption results for 
17 different soils. The regression of log b on the log of the organic 
carbon content of the soils was highly significant. The fit was further 
improved by including pH as a second dependent variant. This probably 
reflected differences in the nature of the organic matter formed in soils 
of different acidity (562). 
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