Analysis and environmental concentrations of the herbicide dichlobenil and its main metabolite 2,6-dichlorobenzamide (BAM): a review

Dichlobenil is an herbicide which has been applied in many countries for weed control in non-agricultural areas such as railroads, car parks and private gardens. In the aquatic environment it has been used for control of floating aquatic weeds. Dichlobenil is relatively persistent in the environment, and primarily bound to solid matrices. Of great concern is its main degradation product 2,6-dichlorobenzamide which is water soluble and therefore transported downward in aquifers, contaminating groundwater resources. It is often found in concentrations exceeding 0.1 μg/L, which is the maximum allowed concentration of pesticides in groundwater set by the European Commission. In many countries, the usage of dichlobenil and the problems associated with groundwater contamination by 2,6-dichlorobenzamide have resulted in intensive research and monitoring of these compounds. This review gives the first overview of analytical strategies available for determining dichlobenil and 2,6-dichlorobenzamide in environmental matrices. It also summarizes studies presenting measured environmental concentrations of dichlobenil and 2,6-dichlorobenzamide identified in the literature during the past two decades. Thereby a preliminary picture of the distribution of dichlobenil and 2,6-dichlorobenzamide in the environment can be outlined for the first time.