Electrochemical investigation of the effect of pH and solvent on amitraz stability

The widespread use of the pesticide amitraz for pest control of crops, livestock and honeybees has warranted several studies aimed at understanding the degradation of this compound during storage and use. In particular the degradation of amitraz and the nature of the toxicologically significant intermediates formed owing to pH and solvent type has been examined. In this study we report on the use of electrochemical methods to monitor amitraz degradation and to identify the major intermediates formed. While this study examines the use of rapid voltammetric methods for such analyses, it also resolves earlier studies showing the rapid degradation of amitraz to 2,4-dimethylaniline without formation of intermediates first, and also suggests that the degradation of amitraz to 2,4-dimethylphenylformamide and to 2,4-dimethylaniline is more rapid than previously observed at pH above 3. These studies also showed that amitraz degrades to dimethylphenylformamide in ethanol and methanol, and is stable in both acetonitrile and dimethylsulphoxide.