大环内酯类抗生素麦迪霉素的电化学特性

在K₂HPO₄,NH₄Cl+NH₃和NaOH的10%(v/v)乙醇水溶液中,除0.01mol·L^-1以上NaOH液作为支持电解质外,麦迪霉素的伏安波皆为两个峰。峰A相当于它的甲醛基还原波,峰B为催化吸附氢波。溶液pH对两峰有强烈的影响。实验表明伏安波有吸附特性,且不可逆。两峰的ip与麦迪霉素的浓度成正比,线性范围分别为3×10^-6～3×10^-5mol·L^-1和1×10^-7～4×10^-5mol·L^-1,检测限为:1×10-6mol·L^-1和5×10^-8mol·L^-1。可应用于麦迪霉素的定量测定。研究了两峰的特性和电极机理,测定了有关的物理常数。

THE ELECTROCHEMICAL BEHAVIOR OF A LARGE RING LACTONE ANTIBIOTIC,MIDECAMYCIN

In the system of K₂HPO₄ or NH₃aqueous solution containing 10%(V/V)alcohol ,the voltammetric waves of midecamycin showed two peaks, but only one peak in NaOH baseelectrolyte.The first peak corresponds to the reduction of an aldehyde group and the second peak is thecatalytic adsorption hydrogen wave. The pH of the solution affects strongly both peakS.Experimentalresults showed that the voltammetric wave of midecamycin has adsorption and the polarographic proce-sses of both peaks are irreversible,The peak currents of both peaks are directly proportional to theconcentration of midecamycin. The linear ranges are 3×10^-6～3×10^-5 mol·L^-1 and 1×10^-7～4×10^-5mol·L^-1and the detection limits are 1×10^-6mol·L^-1 and 5×10^-8 mol·L^-1,respectively.It can be used for the determination of midecamycin. The properties of the peaks and theelectrode mechanism have been studied and some physical constants were determined.