INTERACTION OF AQUATIC HUMIC SUBSTANCES WITH ANILAZINE AND ITS DERIVATIVES - THE NATURE OF THE BOUND RESIDUES

This study is focused on the binding behaviour of the triazine fungici de anilazine and its main metabolites such as dihydroxyanilazine in aq uatic ecosystems. For this purpose anilazine and its derivatives were incubated with ultrafiltrated dissolved organic matter (DOM) and isola ted fulvic and humic acids, respectively and the adsorption isotherms according to Freundlich were determined. More than 90% bound residues were formed and up to 60% of anilazine metabolites were released with a recently developed silylation method. The study of the reactivity of metabolites and model compounds as well as our NMR investigations sho wing ether bondings led to a suggested binding scheme of anilazine to humic substances. To have more realistic conditions the behaviour of a nilazine and dihydroxyanilazine in aquatic model ecosystems with water and sediment from a river was also part of this study. Furthermore th e release of active ingredients or derivatives from sediment by differ ent extraction methods was examined. (C) 1998 Elsevier Science Ltd. Al l rights reserved.