Spectral elucidation of the acid metabolites of the four geometric isomers of trifloxystrobin.

Four geometric isomers of trifloxystrobin (TFS)--namely EE, EZ, ZE, and ZZ--were hydrolyzed by 0.05 M NaOH, resulting in four corresponding acid metabolites. These compounds--namely EE-, EZ-, ZE-, and ZZ-acids--were purified by preparative HPLC and authentically characterized by a combination of infrared, Raman, GC-MS, LC-MS/MS, and NMR spectroscopies. The spectra were found to be very characteristic of the individual isomers, and so they could be used to distinguish the isomers from each other. The detailed spectral features of the individual isomers are presented and compared. EE-acid was identified as being the major metabolite of TFS in soil, which indicates that hydrolysis is the principal route of degradation of TFS. This finding further justifies the importance of the present study in relation to assessing the risk associated with the release of TFS into the environment.