COMPUTER OPTIMIZATION OF BACKGROUND ELECTROLYTE-COMPOSITION IN THE SEPARATION OF METAL-IONS BY CAPILLARY ELECTROPHORESIS

The iterative regression design developed earlier for high performance liquid chromatography (HPLC) has been applied successfully to the opt imization of the separation of 1.1 metal ions by capillary electrophor esis. The parameters used for optimization were pH (over the range 3.5 -5.0) and the concentration of 2-hydroxyisobutyric acid (HIBA) (2-20 m M) used as the complex-forming ligand added to the background electrol yte. Five initial experiments were performed and the response surface was calculated using the relative resolution product as criterion. Thr ee additional experiments were sufficient to establish a stable optimu m, with which all 11 metal ions were separated and well spread in the electropherogram. The total analysis time was less than 5 min.