过氧化氢存在下平行催化氢波法测定红霉素

Determination of Erythromycin Based on Its Parallel Catalytic Hydrogen Wave in the Presence of Hydrogen Peroxide

在pH 6.81的磷酸二氢钾-磷酸氢二钠介质中,红霉素产生一催化氢波,其峰电位(Ep)在-0.80V(vs.SCE);当加入过氧化氢后,该催化氢波被催化,于相同的峰电位处产生一灵敏的平行催化氢波,峰电流增加约15倍,据此提出了平行催化氢波法测定红霉素含量的方法。红霉素的浓度在1.0×10-7～2.6×10-5 mol·L-1范围内与其峰电流二阶导数呈线性关系,检出限(3S/N)为5.0×10-8 mol·L-1。该方法可用于药物制剂中红霉素含量的测定,方法的回收率在92.5%～101%之间;测定片剂样品中红霉素测定值的相对标准偏差(n=7)为2.4%。

In a KH2PO4-Na2HPO4 buffer medium of pH 6.81,a catalytic hydrogen wave of erythromycin was observed at the potential of-0.80 V（vs.SCE）,and upon addition of H2O2,a sensitive parallel catalytic hydrogen wave was observed at the same potential with its peak current increased about 15 times.Based on this fact,a method for the determination of erythromycin by parallel catalytic hydrogen wave was proposed.Linear relationship between values of 2nd derivative of peak current and concentration of erythromycin was kept in the range of 1.0×10-7-2.6×10-5mol·L-1 with detection limit（3S/N） of 5.0×10-8mol·L-1.The proposed method was used in the determination of erythromycin in pharmaceutical preparation,giving values of recovery in the range of 92.5%-101%.In the determination of erythromycin in a tablet sample,value of RSD（n=7） found was 2.4%.