琥乙红霉素在碳糊电极上的电化学测定方法

Electrochemical Determination of Erythromycin Ethylsuccinate Using a Carbon Paste Electrode

以碳糊电极为工作电极,采用循环伏安（CV）法和示差脉冲伏安（DPV）法研究了琥乙红霉素（EEs）在电极上的电化学行为,建立了一种测定EEs的电化学新方法。研究结果表明,在0.1 mol/L磷酸盐（pH=8.0）的缓冲液中,EEs在0.83和0.97 V（vs.SCE）处出现2个氧化峰。用计时安培法（I-t）对EEs进行定量分析,峰电流Ip与琥乙红霉素的浓度分别在2.0×10-7~2.8×10-6mol/L和2.8×10-6~3.1×10-5mol/L范围内呈良好的线性关系检出限（S/N=3）为1.0×10-7mol/L。采用标准加入法测得回收率为95.0%~98.8%,RSD为3.4%（n=3）。该方法具有较高的选择性和灵敏度,可用于药剂中EEs含量的测定,结果令人满意。

A carbon paste electrode used as the working electrode,the electrochemical behavior of erythromycin ethylsuccinate（EEs） was investigated by cyclic voltammetry（CV） and differential pulse voltammetry（DPV）,a novel method was proposed for the determination of EEs.The results showed two irreversible anodic peaks appeared at 0.83 V and 0.97 V,respectively in 0.1 mol/L PBS buffer solution（pH=8.0）,indicating that there were two-step irreversible oxidations.Quantitative measurements by chronoamperometry（I-t） showed that the peak currents were proportional to erythromycin ethylsuccinate concentration in the range of 2.0×10-7~2.8×10-6 and 2.8×10-6~3.1×10-5 mol/L,respectively,with the detection limit（S/N=3） of 1.0×10-7 mol/L.The recovery was in the range of 95.0%~98.8% with a RSD of 3.4%（n=3）.The method showed a high selectivity and sensitivity,and could be used for the determination of EEs in the drugs with satisfactory result.