Chemical and Photochemical degradation of Tribenuron-Methyl in natural liquid phase

Hydrolysis and photo-degradation of tribenuron-methyl in liquid phase were investigated aiming at the assessment of the behaviour of this herbicide in natural conditions. The degradation of this herbicide in ultrapure water and in natural water was compared. A solar simulator apparatus (Suntest CPS+, Heraeus), furnished of a Xenon lamp, was used for herbicide irradiation experiments. Dark experiments were carried out in the same conditions of temperature and concentration. The results obtained show that the degradation of Tribenuron- methyl under irradiation in ultrapure water was faster (as reported in literature) respect to the natural water. The same main degradation product (2-methoxy-4-methylamino- 6-methyl-1,3,5-triazine) was identified after hydrolysis and photoirradiation but in natural water it persisted for a long time. Noticeable: the derivative substance could be toxic as the original compound.