Belal F, Aly F A, Walash M I, Mesbah A O
Department of Analytical Chemistry, Faculty of Pharmacy, University of Mansoura, Egypt.
J Pharm Biomed Anal. 1998 Sep;17(8):1249-56. doi: 10.1016/s0731-7085(98)00039-9.
A highly sensitive polarographic method was developed for the determination of EDTA added as a preservative in certain pharmaceutical preparations. The method involved chelation with Eu(III) followed by polarographic measurement of the chelate formed. A well-defined cathodic wave was developed in Britton-Robinson buffers over the pH range 2-12. The wave was characterized as being quasi-reversible and diffusion controlled. The current-concentration relationship was found to be rectilinear over the ranges 8-160 and 2-120 micrograms ml-1, using DCt and DPP modes, respectively, with limit of detection of 0.1 microgram ml-1 using the DDP technique. The mechanism of the electrode reaction was verified. The proposed method was applied for the determination of EDTA in certain pharmaceutical dosage forms, and the results obtained were in agreement with those obtained by a reference method.
开发了一种高灵敏度极谱法，用于测定某些药物制剂中作为防腐剂添加的乙二胺四乙酸（EDTA）。该方法包括与铕（III）螯合，然后对形成的螯合物进行极谱测量。在pH值为2至12的 Britton-Robinson缓冲液中产生了一个明确的阴极波。该波的特征为准可逆和扩散控制。使用直流极谱法（DCt）和示差脉冲极谱法（DPP）时，电流-浓度关系在8至160微克/毫升和2至120微克/毫升范围内分别呈线性，使用DPP技术的检测限为0.1微克/毫升。验证了电极反应的机理。所提出的方法用于测定某些药物剂型中的EDTA，所得结果与参考方法获得的结果一致。
