A new method of quantification of pipemidic acid by capillary zone electrophoresis with end-column amperometric detection

Capillary zone electrophoresis was employed for the determination of pipemi dic acid using an end-column amperometric detection with a carbon fiber mic rodisk array electrode, at a constant potential of -1.10 V vs, saturated ca lomel electrode. The optimum conditions of separation and detection were 1. 2 x 10(-4) mol/LNaOAc - 8.8 x 10(-4) mol/LHOAc for the buffer solution, 20 kV for the separation voltage, 5 kV and 10 s for the injection voltage and the injection time. The limit of detection was 1.05 x 10(-6) mol/L or 189 a mol (S/N=3). The relative standard deviation was 0.31% for the migration ti me and 2.0% for the electrophoretic peak current. The method was applied to determining pipemidic acid in human serum.