Use of inorganic salts during the etching process in the fabrication of chemically modified capillaries for open tubular electrochromatography

Abstract

Capillaries for use in electrophoretic analyses are etched with ammonium bifluoride and in some cases a second inorganic salt is included in the process. The effects of the presence of these inorganic components in the surface matrix on the electromigration of heterocyclic aromatic amines and enkephalins are evaluated. Resolution, efficiency, and peak shape are used to compare the various columns. In one instance, the etched surface is then modified by the addition of an octadecyl moiety using a silanization/hydrosilation procedure. The surface properties of the various etched capillaries are also compared by electroosmotic flow measurements.