Experiments with c!4+-trifluralin revealed different degradative path- 
ways under aerobic and anaerobic soil condition. Aerobically, degradation 
proceeds through dealkylation and progressive reduction. Anaerobically, 
reduction is followed by dealkylation (1182). 
Aerobic degradation of trifluralin in soil gave rise to small amounts 
of compounds II, III, IV, V, and CO). An unresolved mixture of polar 
products, probably condensed aromatic amines, was also present. Under 
anaerobic conditions in soil, compounds III, VI, VII, VIII and IX were 
observed. A scheme of the postulated metabolic pathways was indicated (553, 
1183). 
Rumen bacteria degraded trifluralin via dealkylation (compound II) and 
reduction of the nitro group (compound VI). Further reduction of compound 
II and dealkylation of compound VI gave rise to metabolite III. The N- 
propylamino-diamino metabolite (VIII) was observed. This could have arisen 
from metabolite III and/or by dealkylation of metabolite VII, which was also 
found. Other unidentified stable metabolites were also observed (1757). 
Studies with trifluralin-exposed Aspergillus niger revealed unchanged 
trifluralin and a small amount of the mono propyl analog; with Sclerotium 
rolfsii Fusaruim sp., and Trichoderma sp., revealed only unchanged trifluralin 
(512). Data from studies with Lachnospira multiparus and bacteroides 
ruminicola subsp. brevis suggested that these organisms alter trifluralin 
with cleavage of a propyl group and reduction of a nitro group to an amine 
CEGEZ>.. 
Pure trifluralin was coated on glass and soil surfaces and exposed to 
sunlight and to ultraviolet light having a wavelength range of 300-700 
millimicorons. Progressive change occurred with time and intensity of 
exposure. The end-product after six hours' exposure to sunlight was red- 
brown in color. Exposure of trifluralin to 4,000 ft-c of light from a 
mercury-vapor source for 4 hours produced similar results. No products 
were identified (1602). 
When dilute heptane solutions of trifluralin in borosilicate glass 
or quartz vials were exposed to ultraviolet light, extensive decomposition 
occurred. The photodecomposition products have not been identified. How- 
ever, the product isolated from N-propyl-2,6-dinitro-4-trifluoromethyl- 
aniline was identified as 2-nitro-6-nitroso-4-trifluoromethylaniline (928). 
326 
