[Research on the variation of peak shape in capillary zone electrophoresis]

The influence of operation conditions, such as, injection time, applied voltage and effective length of capillary column, on parameters of peak shape in capillary zone electrophoresis (CZE) was investigated by using exponential-modified Gaussian (EMG) equation. The CE experiments were carried out by using the sample of derivatives of benzoic acid and small peptides. The experimens indicated that there was a significant effect of injection time on W1/2 and that the peaks changed from tailing to leading when the injection time was over 3 seconds in the case of pressure injection. It is recommended that an injection time less than 3 seconds can lead to a good column efficiency. The good linear relationships between tm and tau, sigma, W1/2 (t) with different separation voltages were observed. In the range of experimental conditions (11-27kV), higher voltage could lead to smaller zone dispersion, giving rapid and high efficient separation, and the voltage was insignificant on peak tailing. It was also shown that sigma, tau and W1/2 increased slightly with increasing the effective length of capillary column.