Analysis of Carbamate and Urea Herbicides in Foods, Using Fluorogenic Labeling

Abstract

Abstract A procedure using fluorogenic labeling for the analysis of carbamate and urea herbicides in several food types has been developed. Extracted herbicides are hydrolyzed to their corresponding anilines, which are then labeled with dansyl chloride (1-dimethylaminonaphthalene- 5-sulfonyl chloride). The reaction is carried out on a thin layer plate which is subsequently developed, and the separated spots are either scanned for fluorescence or are removed from the layer and quantitatively analyzed in solution by fluorometry. As low as 0.05 ppm herbicide can be detected with no interference from coextractives. Other than a single partition step from the extracting solvent no cleanup is required. The method may be used for confirmation of the identity of a number of carbamate and urea herbicides, as a quantitative analytical technique where equipment is available, or as a method for screening where only the knowledge of herbicide presence is required.