单扫描示波极谱法测定片剂中的二甲双胍

Single sweep oscillopolarographic technique for the determination of metformin in tablets

在0．10mol／L的HAc—NaAc（pH=4．3）溶液中二甲双胍于-1．44V（vs．SCE）处产生一个灵敏的极谱波，其二阶导数峰峰电流ip”与二甲双胍浓度在1．0×10^-7～1．4×10^-5mol／L范围内呈良好的线性关系（r=0．9972），检测下限为8．0×10^-8mol／L，相对标准偏差（RSD）为1．3％；并研究了一些常见离子及有机物对测定的影响．通过循环伏安法、电解法等方法证明二甲双胍在汞电极上产生的还原波是催化氢波，并推导出其电极反应机理．该法成功用于片剂中二甲双胍的测定，回收率在97．2％～103．0％之间．

A single sweep oscillopolarographic method for the determination of metformin has been studied. Metformin exhibits a sensitive cathodic wave at -1.44 V （vs. SCE） in 0.10 mol/L HAc-NaAC buffer （pH=4.3）. The linear concentration range of application was 1. 0 ×10^-7～1.4×10^-5 mol/L of metformin, with a relative standard deviation of 1.3% （for a level of 2.0×10^-6 mol/L） and a detection limit of 1.0 × 10^-7 mol/L. The polarographic behavior of meformin showed that the reduction wave was a catalytic hydrogen wave, which was the reduction of the proton combined with metformin in nature. The method was successfully applied to the direct determination of metformin in tablets with standard addition recoveries of 97.2% ～103.0%. The proposed method is simple, cheap and time-saving.