NUCLEAR-MAGNETIC-RESONANCE IDENTIFICATION OF NEW SULFONIC-ACID METABOLITES OF CHLOROACETANILIDE HERBICIDES

The detection of the sulfonic acid metabolites of the chloroacetanilid e herbicides acetochlor, alachlor, butachlor, propachlor, and, more re cently, metolachlor in surface and ground water suggests that a common mechanism for dechlorination exists via the glutathione conjugation p athway. The identification of these herbicides and their metabolites i s important due to growing public awareness and concern about pesticid e levels in drinking water. Although these herbicides are regulated, l ittle is known about the fate of their metabolites in soil. The sulfon ic acid metabolites were synthesized by reaction of the parent compoun ds with an excess of sodium sulfite. Acetochlor alachlor, butachlor, m etolachlor, and propachlor and their sulfonic acid metabolites were st udied by nuclear magnetic resonance spectroscopy and fast atom bombard ment mass spectrometry. This paper provides a direct method for the pr eparation and characterization of these compounds that will be useful in the analysis and study of chloracetanilide herbicides and their met abolites.