格列美脲的极谱行为及测定

Polarographic behavior and determination of glimepiride

目的建立灵敏快速测定格列美脲的新方法。方法用氧化剂存在时格列美脲产生的极谱催化波提高分析灵敏度,用线性单扫描极谱法实现快速测定。结果在Na2B4O7KH2PO4支持电解质中,格列美脲产生1个催化氢波。加入K2S2O8后,该催化氢波被催化,峰电流增加约25倍,峰电位基本不变,产生1个较灵敏的平行催化氢波。其二阶导数峰峰电流ip″与格列美脲浓度在1.0×10-7～4.2×10-5mol·L-1呈线性关系,检出限为5.0×10-8mol·L-1。结论该方法可用于药物制剂中格列美脲含量的测定。

Aim To establish a polarographic method of parallel catalytic hydrogen wave for determination of glimepiride. Methods The catalytic wave of glimepiride in the presence of K2S2O8 was used to improve the analytical sensitivity. The rapid determination of glimepiride was done by linear single sweep polarography. Results The catalytic hydrogen wave of glimepiride was measured at ca. - 1.36 （ vs SCE） in 0. 09 mol·L^-1 Na2B4O7-KH2PO4 （pH 6.24±0.1 ） supporting electrolyte. When 1.0×10^-2 mol·L^-1 K2S2O8 was present, the current increased by 25 times, and the peak potentioal was unchanged, producing a more sensitive parallel catalytic hydrogen wave. The peak current of the parallel catalytic hydrogen wave was rectilinear to the glimepiride concentration in the range 1.0×10^-7 - 4. 2×10-5 mol· L^-1 （r = 0.9990, n = 9）. The detection limit was 5.0×10^-8 mol· L^-1. Conclusion The proposed method could be applied to the determination of glimepiride in pharmaceuticals without preliminary separation.