No abstract

Carbetamide [D( -) -phenylcarbamoyloxy -2 -(Naniline which were converted to the corresponding ethylpropionamide)] is a selective herbicide which amides with 4-bromobenzoyl chloride. The amides controls weeds in alfalfa and cereals by preemerwere then separated by column chromatography on gence and/or postemergence applications. TheFlorisil. The limits of detection of these derivatives parent compound and its aniline metabolite were by electron-capture gas chromatography were genseparated by liquid-liquid partition of the crop erally less than 0.05 ppm and in some cases less extract. After acid hydrolysis the carbetamide than 0.02 ppm. afforded quantitative yields of ethylamine andpropionamide)] is an experimental selective herbicide C produced by Rhone-Poulenc, France. Since the compound is being considered for the control of certain weeds in cereals, wheat, barley, forages, and alfalfa by preemergence and/or postemergence applications, a method was needed to determine the residues of this material. In studying its metabolism, Desmoras et af. (1967) found that aniline was present in plants in small quantities soon after treatment with the parent compound, but was rapidly eliminated. The degradation of carbamates in soil and crops has been extensively studied (Kaufman, 1967, for leading references) and aniline derivatives have been reported as metabolites of phenyl carbamates. Tilden and Van Middlelem (1970) succeeded in determining carbaryl as the amide derivative with electron-capture gas chromatography. The object of the present investigation was to develop a method that would be specific for carbetamide and at the same time detect the aniline metabolite.

EDITOR B2, Gi, G2, and BiA under the conditions of the experiment. Differences in the behavior of strains of C. pyrenoidosa and C. vulgaris to the action of various herbicides can be and have been attributed to strain differences (Vance and Smith, 1969; Thomas et al., 1971) and to differences in growth conditions. By changing from autotrophic conditions to heterotrophic conditions by the addition of a reduced carbon source such as glucose, it has been shown that the inhibitory effects of some herbicides which affect the photosynthetic process on strains of C. pyrenoidosa and C. vulgaris can be reversed (Geoghagen, 1957; Ashton et al., 1966; Sikka and Pramer, 1968). In order to reduce the time of the assay and in order to avoid special provisions for a carbon dioxide source, glucose has been used as a carbon source under our conditions.The results presented here emphasize the importance of strain differences when Chlorella is used as a test organism. LITERATURE CITED