Photocatalysed degradation of cyromazine in aqueous titanium dioxide suspensions: comparison with photolysis

The fate of cyromazine (N-cyclopropyl-1,3,5-triazine-2,4,6-triamine), an in sect growth regulator, has been studied upon irradiation as well as its pho tocatalytic treatment (advanced oxidation technology). Most of the organic compounds occurring during the photodegradation have been identified by mea ns of liquid chromatography and mass spectrometry coupled techniques (LC-MS ). The main photoproducts of the first degradation steps are amide-triazine s and melamine. Simultaneously, carboxylic acids, such as acrylic, pyruvic and glycolic acids have been identified by LC-UV. These acids are resulting from the cyclopropyl degradation. The melamine (1,3,5-triazine-2,4,6-triam ine) is transformed into cyanuric acid (2,4,6-trihydroxy-1,3,5-triazine) by means of three successive deaminations. This compound remains very stable in aqueous solution, (C) 2001 Elsevier Science B.V, All rights reserved.