Atrazine dealkylation on a manganese oxide surface

In this paper we report the first observation of abiotic N-dealkylation of the herbicide, atrazine[6-chloro-N-ethylN "-(l-methylethyl)- 1,3,5-triazine-2,4-diamine], by synthetic manganese oxide (delta-MnO(2)). The degradation reaction of the adsorbed herbicide was quantified at 30 degrees C by combined calorimetry, manometry, gas chromatography-mass spectrometry, liquid chromatography, and electron spin resonance spectroscopy. These combined methodologies gave clear evidence for the production of N-dealkylated forms of atrazine over a 48 h period of reaction on the surface of delta-MnO(2). This surface-catalyzed, non-photochemical abiotic N-dealkylation of the herbicide differs from known microbial pathways in soils by a higher rate of reaction and a different distribution of products among N-dealkylated forms. (C) 1998 Elsevier Science B.V.