Identification and confirmation of atrazine in pond water

A fish kill in a farm pond prompted examination of the water. The neighbouring farmland had been treated with an organophosphate, a thiocarbazide, and Bladex (a triazine). Residues of the first two pesticides were not identified; only atrazine could be detected in the farm pond; the origin was unknown. However, a sequence of atrazine formation in the soil has been proposed: degradation of the nitrile to an amide and then to an acid, with subsequent decarboxylation. Thus atrazine could have been derived from Bladex (cyanazine), but considering the persistence and stability of atrazine, the surrounding farmland could also have been treated with atrazine in previous years and still have been in suspension in the farm pond. The origin of the atrazine could not be fully elucidated.