Abstract: With Co ion implantation modified carbon fiber ultramicroelectrode as the working electrode, in_0.1 mol/L HAc-NaAc(pH=5.05) buffer solution, a sensitive reductive peak of pirarubicin was obtained by linear sweep voltammetry. The peak potential was-0.520 V( vs . SCE). The peak current was proportional to the concentration of pirarubicin over the range of 1.0×10^{-7 6}.0×10^-6 mol/L, with a detection limit of 5.0×10^-8 mol/L. This method has been developed for the determination of pirarubicin in human urine. The recoveries were in the range from 91.6% to 106.7%. The experiments showed that the reduction process of pirarubicin was a reversible process with adsorption. The composition and depth distribution of elements on the surfaces of Co ion implantation modified carbon fiber microelectrode were determined by scanning electron microscope and Auger electron spectroscopy. The experiments showed that Co was surely implanteDInto the surface of carbon fiber, and the implanted Co catalyzed the reduction of pirarubicin.

Key words: Pirarubicin, Electrochemical behavior, Ion-implantation, Modified ultramicroelectrode