| The pre-emergence herbicide atrazine is a common weed preventative in corn, rice, and sugarcane fields. Analysis of field and laboratory samples has shown a wide array of metabolites formed by both microbial and abiotic degradation. The non-phytotoxic metabolite, hydroxyatrazine, can be produced both microbially and by chemical processes in soil; however, it has not been possible to predict with any certainty exactly what physico-chemical conditions will result in the appearance of hydroxyatrazine. This work reviews the field and laboratory research data on atrazine degradation, and finds that some key physico-chemical data is missing.;Density functional theory is used to model the reaction of atrazine with water under acidic conditions. The results of these calculations indicate that atrazine is hydroxylated abiotically through a novel reaction mechanism: acid catalyzed nucleophilic aromatic substitution. |
