DEGRADATION OF HERBICIDE-RELATED NITROSAMINES IN AEROBIC SOILS

Four 14C-labeled nitrosamines were incorporated into aerobic soils, and the rate of 14C02 production was measured. Rates of 14C02 evolution were similar for N-nitrosodipropyl-, diethyl-, and dimethylamines.Samples of nitrosodipropylamine individually labeled with 14C at carbons 1, 2, and 3 were synthesized.The rate of 4C02 production was independent of the position of the label. The reaction is believed to be microbiological because sterilization of the soil inhibited C02 production. For a few days after application, volatilization of unchanged nitrosaminefrom soil also occurred. It is estimated that the half-life of these nitrosamines in aerobic soils is on the order of three weeks. N-Nitrosopendimethalin[N-(1-ethylpropyl)-N-nitroso-3, 4-dimethyl-2, 6-dinitrobenzenamine] was relatively stable in soil and significant quantities could be recovered unchanged after several months. © 1979, American Chemical Society. All rights reserved.