Degradation of atrazine into ammeline by combined ozone/hydrogen peroxide treatment in water

The aqueous ozone treatment of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] in the presence of hydrogen peroxide was reinvestigated using a new tandem solid-phase extraction procedure which includes a C-18 reverse phase support and a strong cation exchanger. In this way, both chlorotriazines and the more polar hydroxytriazines could be analyzed to establish total molar balances of degradation products vs the initial pesticide in the 45-55% range. In all the experimental conditions examined (treatment rates, pH, and eventual presence of carbonates), ammeline (2,4-diamino-6-hydroxy-s-triazine) was found as the major end-product (20% at pH 8). 2-Chloro-4,6-diamino-s-triazine was produced competitively, and the ratio between both products was dependent on the hydroxyl radical content. A number of new intermediates were identified i.e. amino-aldehydes and a carbinolamine. The carbinolamine functionality is of great interest since being involved in the dealkylation process of the triazinic amino groups.