大环内酯类抗生素麦迪霉素的电化学特性

THE ELECTROCHEMICAL BEHAVIOR OF A LARGE RING LACTONE ANTIBIOTIC,MIDECAMYCIN

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３×１０－６～３×１０５－５ｍｏｌ·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。

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.