Zinophos' [0,0-Diethyl 0-2-pyrazinyl phosphorothioate ] 
The persistence of zinophos in soil was studied in the laboratory 
and in the field. A curvilinear regression equation was derived that 
could be applied satisfactorily to the degradation curves (544). 
y=b, +b, x + box!” 
After soil was treated with zinophos, the hydrolysis product 2- 
pyrazinol was detected. The oxygen analog of zinophos was unstable in 
soil and was not detected. When c!4_ying-labeled zinophos was used, 
c!40, was also observed (542). Information available indicated that the 
hydrolytic product 2~pyrazinol was rapidly metabolized to smaller 
fragments (787). 
Zytron [0-(2,4-Dichlorophenyl) O-methyl N-isopropylphosphoramidothioate ] 
Aspergillus clavatus degraded zytron. Small amounts of 2,4~dichloro- 
phenol were detected but the latter did not accumulate (451). 
347 
