Determination of carbetamide residues and its aniline metabolite

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.

Determination of residues of carbetamide and its derivatives in the soil and in field-grown lettuce

“…The final extract was analysed further by m.s. Furthermore, an aliquot of the benzene extract was derivatized using P-bromobenzoylchloride, which transformed aniline into 4-bromo-N-phenylbenzamide according to a described procedure (Guardigli et al, 1972). In this way, aniline present as such in the soil was measured simultaneously as two different derivatives using both g.l.c, and m.s.…”

“…The method available (Guardigli et al, 1972) for the analysis in plant is not applicable to soil analysis, because both compounds are strongly absorbed on soil. In the present work, we studied the fate of carbetamide in soil of lettuce fields, and the uptake of both carbetamide and its aniline metabolite by the lettuce plant.…”