Bovine erythrocyte AcCh 

Affinity =Ka(,™) Phosphorylation ep Caitar 
Malaoxon (dl) 3.6 * 0.23 Se Ore 2 Tht 
Malaoxon (d) Ze oe O23 63.0 * 3.2 
Malaoxon (1) , 4.9°2 0.51 Sh Out 2 
(1788) 
Using a rat liver carboxylesterase, the hydrolysis of malathion was 
investigated. NMR and infrared spectroscopy established that the monoacid 
was identical with the monoacid isolated from rat urine after oral admini- 
stration of malathion. This was determined to be 0,0-dimethyl-S-(1l-carboxy- 
2-carbethoxy)ethyl phosphorodithioate (a-monoacid) (17/76). 
Degradation rates of dusts at various temperatures were fitted to 
Jander's rate equation, when the rate of degradation did not exceed 804 
(1389). 
KE = [iett-aj2/ 77" 
a = reaction rate 
k = degradation rate constant 
t = reaction time 
Teo} k x 10° 
Malathion dust 
(Room temp.) 0.4 
30 xek 
40 i 
50 36 
60 150 
235 
