metabolite had a M.W. = 358 and contained 5 chlorine atoms. Infrared spectra 
indicated the presence of an epoxide and a carbonyl and the absence of 
C1-C=C-Cl1. The compound formed a 2,4-dinitrophenylhydrazone. The results 
lead to the molecular formula of Cj,9H7C1>509 and the structure 1,9,10,10,11- 
exo-pentachloro-4 , 5-epoxy-pentacyclo-(7,3,0,0,7°°,0978 97711) dodecan’ isons 
for the urinary metabolite (XI). 
The M.W. of the fecal metabolite was 394 and contained 6 chlorine atoms. 
Infrared spectra of the fecal metabolite indicated Cl-C=C-Cl, and -CH>-, 
tertiary hydroxy, and an epoxide. This plus mass spectra lead to the empirical 
formula Cj 9HgClg0) and the structure 1,2,3,4,10,10-hexachloro-6, 7-epoxy- 
1,4,4a,5,6,7,8,8a-octahydro-4a(or 5)-hydroxy-exo-1,4-endo-5 , 8-methanonaphalene 
(XII) (1591, 1658). 
Regression lines for the relationship between concentration of dieldrin 
in tissues of pigeons was determined and an equation derived showing the 
change of concentration in the whole pigeon when exposure ceases. 
where b=0.0064 
Cy =Concentration of dieldrin when exposure ceases. 
From this relationship, the half-life of dieldrin in the pigeon has been 
calculated. 
(Ponti PCB Gg" . 47.2 days “(Pa0295,41,4.- 54.9) 
i 
b 
An elimination mechanism of the type indicated by the equations implies that 
continuous uniform exposure will result in an equilibrium concentration in 
tissues expressed by equation (3). 
(3) C_=C (tee =} where 
t eq 
C. = concentration at time t 
= > C > © 
yee the asymptote (C. » as t 
b = the slope of regression line when concentrations are transformed 
to corresponding logarithms. 
(1225) 
Urine of men with occupational exposure to dieldrin gave evidence that 
dieldrin was eliminated in humans as at least two neutral, polar, chlorinated 
metabolites, thus far unidentified (320, 464). 
26 


