Gupta V K, Singh A K, Gupta Barkha
Department of Chemistry, Indian Institute of Technology-Roorkee, Roorkee 247667, India.
Anal Bioanal Chem. 2007 Nov;389(6):2019-28. doi: 10.1007/s00216-007-1560-0. Epub 2007 Sep 14.
Newly developed, simple, low-cost and sensitive ion-selective electrodes have been proposed for determination of some antiepileptic drugs such as lamotrigine, felbamate, and primidone in their pharmaceutical preparations as well as in biological fluids. The electrodes are based on poly(vinyl chloride) membranes doped with drug-tetraphenyl borate (TPB) or drug-phosphotungstic acid (PT) ion-pair complexes as molecular recognition materials. The novel electrodes displayed rapid Nernstian responses with detection limits of approximately 10(-7) M. Calibration graphs were linear over the ranges 5.2 x 10(-7)-1.0 x 10(-3), 1.5 x 10(-6)-1.0 x 10(-3), and 2.6 x 10(-7)-1.0 x 10(-3 )M for drug-TPB and 5.8 x 10(-7)-1.0 x 10(-3), 1.8 x 10(-7)-1.0 x 10(-3), and 6.6 x 10(-7)-1.0 x 10(-3) M for drug-PT electrodes, respectively, with slopes ranging from 52.3 to 62.3 mV/decade. The membranes developed have potential stability for up to 1 month and proved to be highly selective for the drugs investigated over other ions and excipients. The results show that the selectivity of the ion-selective electrodes is influenced significantly by the plasticizer. The proposed electrodes were successfully applied in the determination of these drugs in pharmaceutical preparations in four batches of different expiry dates. Statistical Student's t test and F test showed insignificant systematic error between the ion-selective electrode methods developed and a standard method. Comparison of the results obtained using the proposed electrodes with those found using a reference method showed that the ion-selective electrode technique is sensitive, reliable, and can be used with very good accuracy and high percentage recovery without pretreatment procedures of the samples to minimize interfering matrix effects.
已提出新开发的、简单、低成本且灵敏的离子选择性电极，用于测定某些抗癫痫药物，如拉莫三嗪、非氨酯和扑米酮，这些药物存在于其药物制剂以及生物流体中。这些电极基于掺杂有药物 - 四苯基硼酸（TPB）或药物 - 磷钨酸（PT）离子对配合物作为分子识别材料的聚氯乙烯膜。新型电极显示出快速的能斯特响应，检测限约为10(-7) M。校准曲线在5.2×10(-7) - 1.0×10(-3)、1.5×10(-6) - 1.0×10(-3)和2.6×10(-7) - 1.0×10(-3) M（药物 - TPB电极）以及5.8×10(-7) - 1.0×10(-3)、1.8×10(-7) - 1.0×10(-3)和6.6×10(-7) - 1.0×10(-3) M（药物 - PT电极）范围内呈线性，斜率范围为52.3至62.3 mV/十倍。所开发的膜具有长达1个月的电位稳定性，并且被证明对所研究的药物相对于其他离子和辅料具有高度选择性。结果表明，离子选择性电极的选择性受增塑剂的显著影响。所提出的电极已成功应用于测定四批不同有效期的药物制剂中的这些药物。统计学生t检验和F检验表明，所开发的离子选择性电极方法与标准方法之间无显著系统误差。将使用所提出的电极获得的结果与使用参考方法获得的结果进行比较表明，离子选择性电极技术灵敏、可靠，并且无需对样品进行预处理程序以最小化干扰基质效应，即可以非常高的准确度和高回收率使用。
