Symmetric and Asymmetric Copper Selective Electrodes based on N-(benzothiazol-2-ylcarbamothioyl)benzamide

Document Type : Original Article


Department of Chemistry, Yadegar-e-Imam Khomeini (RAH) Shahre Rey Branch, Islamic Azad University, Tehran, Iran


The present work aimed at comparing the capabilities and efficiency of symmetric and asymmetric electrodes for potentiometric detection of Cu2+. Initially, we synthesized N-(benzothiazol-2-ylcarbamothioyl)benzamide, and 1H-NMR, 13C-NMR, and FT-IR spectroscopy approaches were used for characterization. Subsequently, it was employed as an ionophore to fabricate asymmetric electrodes of coated wire (CWE) and solid-state (SSE) and symmetric electrodes with liquid internal electrolyte (LIE). The best liquid membrane was prepared with an Ionophore: DBP: PVC: NaTPB ratio of 12:56:30:2. All electrodes exhibited Nernstian responses. The detection limits for SSE (1×10-9 mol/L) and CWE (1×10-7 mol/L) were superior to LIE (2×10-6 mol/L). Moreover, all three electrodes demonstrated very short response times (approximately 6 seconds) and exhibited large selectivity coefficient values for different cations. Asymmetric electrodes displayed longer lifetimes (SSE: 13 weeks and CWE: 12 weeks) compared to the symmetric electrode (LIE: 10 weeks). Finally, the electrodes were utilized for potentiometric titration of Cu2+ with ethylenediaminetetraacetic acid.


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