ENANTIOMERIC AND ISOMERIC SEPARATION OF HERBICIDES USING CYCLODEXTRIN-MODIFIED CAPILLARY-ZONE-ELECTROPHORESIS

Cyclodextrin-modified capillary zone electrophoresis (CD-CZE) was appl ied successfully to the enantiomeric and isomeric separation of three herbicides (imazaquin, diclofop and imazamethabenz). Commercially avai lable cyclodextrins were evaluated for separation of the enantiomers a nd isomers of the three herbicides having Varied molecular structures. The enantiomers of imazaquin and diclofop, and the isomers of imazame thabenz could be resolved with a resolution of greater than or equal t o 1.5. The resolution was found to depend on pH of the run buffer, cyc lodextrin type and cyclodextrin concentration. By employing mixed cycl odextrins in the running buffer, the three herbicides were simultaneou sly separated in a single run. In addition, rapid (less than 3 min) en antiomeric separation is demonstrated using imazaquin as a model herbi cide. The reported capillary electrophoresis (CE) methods are simple, rapid, efficient and reproducible and our results demonstrate that CE provides a powerful analytical tool for enantiomeric and isomeric sepa ration of herbicides. (C) 1997 Elsevier Science B.V.