ATRAZINE DEALKYLATION ON A MANGANESE OXIDE SURFACE

In this paper we report the first observation of abiotic N-dealkylatio n of the herbicide, atrazine[6-chloro-N-ethylN ''-(l-methylethyl)- 1,3 ,5-triazine-2,4-diamine], by synthetic manganese oxide (delta-MnO2). T he 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 spec troscopy. These combined methodologies gave clear evidence for the pro duction of N-dealkylated forms of atrazine over a 48 h period of react ion on the surface of delta-MnO2. This surface-catalyzed, non-photoche mical abiotic N-dealkylation of the herbicide differs from known micro bial pathways in soils by a higher rate of reaction and a different di stribution of products among N-dealkylated forms. (C) 1998 Elsevier Sc ience B.V.