Electrochemical Sensor Based on Crafted Thia Polymeric Crown Ether for Determination of Carbamazepine and Ephedrine

Background: Direct analysis methods are considered some of the best and easiest tools to quickly determine the amount of active drug in some pharmaceutical preparations. Objectives: In this study, an ion electrode is prepared to determine the concentration of a sample of ephedrine (Eph) and carbamazepine (CBZ) in the medicines produced by some companies directly. Methods: CBZ and Eph drugs ion-selective electrode (ISE) based on Thia polymeric crown ether (SPCE-CZB and SPCE-Eph) as membrane carrier in polyvinyl chloride (PVC) matrix was successfully fabricated for the determination of CBZ and Eph drugs. Results: The electrode exhibited a liner Nernstian slope response over the range of 1×10-1 to 1×10-6 M, and 1×10-5 to 1×10-1 with a slope of 28 and 33±2 mV per decade charge, respectively, by using dimethyl phthalate plasticizer and a detection limit of 1×10-9 M. The response time of the sensor was 10 s. The ISE showed a greater preference for CBZ and Eph over other drugs with good precision. Conclusion: The selectivity coefficients of some drugs ranged from 1×10-5 to 1×10-1. Meanwhile, SPCE-CZB (ISE) was successfully used as an indicator electrode for the potentiometric determination of the CBZ drug pharmaceutical formulas.