THE EFFECT OF OPERATING PARAMETERS ON THE ANALYSIS OF A HUMAN ALPHA-INTERFERON BY CAPILLARY ZONE ELECTROPHORESIS

The influence of the operating parameters in capillary zone electrophoresis (CZE) on the separation of a human alpha-interferon has been investigated. The separation was characterised by the electrophoretic mobility of the first and last observed peaks, and the number of peaks on the electropherogram, whether visible as shoulders or adequately resolved. No peaks could be observed at lower pH values (below pH 4.7) due to capillary wall adsorption. The optimum pH (pH 6.1) for the CZE analysis of human alpha-interferon was close to the isoelectric points of the sample components (pI 5.5 6.5). The investigation of the effect of the berate, phosphate and Trizma buffer concentration on the separation showed that increasing buffer concentration generally decreases the electrophoretic mobility with increased resolution, up to a certain optimum. Longer capillary lengths and slightly higher voltages also increased the resolution. The maximum number of peaks (17) was observed by using 200 mM phosphate buffer (pH 6.1) with 50 cm effective length capillary applying 12 kV voltage.