Subject(s)
Herbicides , Picolinic Acids , Carbon Radioisotopes , Chemical Phenomena , Chemistry , Chlorine , Drug Stability , Free Radicals , Models, Chemical , Nitrogen , Pesticide Residues , Photolysis , Sodium , Sodium Chloride , Ultraviolet RaysABSTRACT
Both as a pure solid and in hexane solution, DDT readily decomposed when irradiated with ultraviolet light (2537 angstroms). Principal products identified by gas-liquid and thin-layer chromatography from irradiations of the solid phase were 1,1-dichloro-2,2-bis (p-chlorophenyl) ethane, 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene, and 4,4'-dichlorobenzophenone. 1,1-Dichloro-2,2-bis(p-chlorophenyl) ethane and hydrochloric acid were identified from irradiated solutions of DDT in hexane. On the basis of products obtained, quantum yields, scavenger experiments, and other chemical tests, a nonchain, free-radical mode of degradation is proposed.
Subject(s)
DDT/radiation effects , Radiation Effects , Ultraviolet Rays , Dichlorodiphenyldichloroethane/radiation effects , Free Radicals , Light , RadiochemistryABSTRACT
DDT labeled with carbon-14 was added to soil, and the mixture was incubated anaerobically for 2 weeks and 4 weeks. DDT and seven possible decomposition products were separated by thin-layer chromatography, and the radioactivity of material from individual spots was determined by liquid scintillation. The DDT was dechlorinated by soil microorganisms to DDD, and only traces of other degradation products were detected. No degradation of DDT was detected in sterile soil.
