Selective square wave voltammetric determination of tinidazole in pharmaceutical formulations, and human urine samples using poly(bis(2,2′-bipyridine)diresorcinolateruthenium(III) chloride) modified glassy carbon electrode

This study reports the determination of Tinidazole (TDL) using a modified glassy carbon electrode, poly(bis(2,2′-bipyridine)diresorcinateruthenium(III) chloride) (poly(BBPDRRuC)/GCE) by a newly synthesized mixed ligand complex, bis-(2,2′-bipyridine)diresorcinateruthenium(III) chloride(BBPDRRuC). Electrochemical impedance spectroscopy (EIS) and cyclic voltamettry (CV) results demonstrated modification of the surface of the electrode by a conductive, and electroactive polymer film leading to an enhanced effective electrode surface area and their electrocatalytic role. Appearance of an irreversible reductive peak at much reduced potential with four folds current enhancement at poly(BBPDRRuC)/GCE showed the catalytic effect of the modifier by reduction of TDL. Square wave voltammetry current response of poly(BBPDRRuC)/GCE showed linear dependence on concentration of TDL in the range 10⁻⁸˗ 3.0 × 10⁻⁴ M with LoD and LoQ of 2.5 nM, and 8.2 nM, respectively. The TDL level in the studied tablet brands were in the range 96.6–101.1% of their labeled values. Spike recovery results in tablet, and human blood serum samples were in the range 98.3˗100.4%, and 98.85 ˗ 99.89%, respectively, and interference recovery results with <4.5% error. The developed method required a simple electrode modification step, a relatively chip, an easily available and non-toxic modifier, provides the least LoD, and reasonably wider linear dynamic range, and had excellent performance for the determination of TDL in tablet formulation and serum samples as compared with recently reported voltammetric methods.