COAXIAL CAPILLARY AND CONDUCTIVE CAPILLARY INTERFACES FOR COLLECTION OF FRACTIONS-ISOLATED BY CAPILLARY ELECTROPHORESIS

An instrument is described that allows the automated collection of fra ctions isolated by capillary electrophoresis, This instrument allows t he electrical connection to be established with the separation capilla ry by using a coaxial capillary how cell or by treating the outer surf ace of the capillary with a gold-filled epoxy to allow electrophoresis , The coaxial interface is most useful when the electroosmotic now in the capillary is small, and the conductive capillary interface is favo red when dilution and contamination of the sample must be minimized, B oth geometries permit closely spaced fractions to be acquired with min imal cross-contamination and dilution, Sample recoveries were better t han 80% and virtually independent of the chemical characteristics of t he sample. Fractions isolated with this instrument were successfully a nalyzed by high-pressure liquid chromatography and electrospray mass s pectrometry.