CLUSTER-ANALYSIS APPLIED TO THE SELECTION AND COMBINATION OF BUFFERING ELECTROLYTE SYSTEMS USED FOR CAPILLARY ELECTROPHORESIS OF ANIONS WITH WATER OR METHANOL AS SOLVENTS

The use of methanol as a solvent for buffering electrolyte systems used for the electrophoresis In capillaries was examined by cluster analysis. For this general approach, four methanollc electrolyte systems with different pH values were compared with eight aqueous systems. The similarity between these 12 systems was described by the Euclidian distances, calculated from the values of the electrophoretic mobilities of 55 anions. Clusters were constructed by use of a hierarchic algorithm and delineated by dendrograms. On the basis of the structures of the clusters, an appropriate selection Is derived for the combination of electrolyte systems. It was found, that at least one methanollc system must be selected for the most favorable combination of three systems. Besides a physicochemical Interpretation, the validity of the clusters was empirically proved by comparison with clusters formed by systems characterized by attributes with randomly generated values. © 1990, American Chemical Society. All rights reserved.