Abstract: Capillary electrophoresis(CE) was employed to separate polyhydroxy antibiotics in alkaline solution, combined with electrochemical detection at copper electrode. The electrode used was a 350 μm diameter Cu disk operated in a wall-jet configuration. Asample mixture containing 7 different polyhydroxy antibibeics was separated within 30min. The linearity varied over a 2-3 order of magnitude and the detection limits were 0.5 μmol/L.The reproducibility for the peak current and the migration time of 50 μ mol/Ldoublemycin injected every hour in a period of 8h, was 7.6% and 2.2% RSD, respectively, and the recovery of the determination of the real sample was 99.6%.

Key words: Capillary electrophoresis, Electrochemical detection, Polyhydroxy antibiotics, Copper electrode