PERSISTENCE OF SOME PHENYLAMIDE PESTICIDES IN AQUATIC ENVIRONMENT .1. HYDROLYSIS

Phenylamide pesticides are a group of closely related compounds, i.e., phenylcarbamates, phenylureas and anilides. Those included were: isopropyl N-phenylcarbamate, isopropyl-N-(3-chlorophenyl)-carbamate, monuron, diuron, linuron, neburon, propanil, dicryl, Baylucide and Vitavax. Their hydrolysis in aqueous solutions and the kinetics of the reaction were investigated. The observed reactivity of phenylamides and their susceptibility for nucleophilic attack by OH- are mainly linked with the polarity of the carbonyl C. Hydrolysis at measurable rates was only affected in high alkaline solutions. At pH values which dominate in natural surface waters, these compounds are liable to maintain their stability and chemical hydrolysis will be a minor route for their degradation in the aquatic environment.