Determination of transformation products of agrochemicals in water and soil

The photolysis of selected pesticides in aqueous solutions has been investi gated. The photolysis produced different intermediate substances, which wer e also found to be soil and microbial degradation products. The phototransf ormation in the presence of TiO2 and humic substances leads to a disappeara nce of these compounds. In terrestrial ecosystems, pesticides compounds are dechlorinated and converted to various transformation products. Mineraliza tion rates and the formation of soil-bound residues depend on the degree of chlorination as well as on other substituents in the molecule.