The determination of substituted phenylurea herbicides and their impurities in technical and formulated products by use of liquid chromatography

Abstract

The application of liquid chromatography to the identification and determination of the active ingredient and the impurities in phenylurea herbicides commonly employed in agriculture is described. Technical materials are dissolved in dichloromethane and chromatographed on microparticulate silica with dichloromethane or dichloromethane-methanol as eluting agent, or on microparticulate silica bonded with octadecyltrichlorosilane with methanol-water as eluting agent. An initial extraction procedure is required for dispersible powders. Detection was by means of ultraviolet absorbance.