Fabrication of chemically modified carbon paste electrode based on functionalized biopolymer for potentiometric determination of Al (III) ion in real water and pharmaceutical samples

Abstract

Carbon paste electrode modified with Carboxymethyl chitosan-graft-poly(1-cyanoethanoyl-4-acryloyl-thiosemcarbazide)copolymers(CMCS-PCEATS) as ionophore was constructed for potentiometric determination of aluminum (III) and the chelation between the ionophore and the aluminum (III) ions at the electrode surface was characterized using SEM, EDX, and IR analysis. Thermal stability of the prepared electrode before and after chelation with the metal ion was investigated. The highest performance was obtained with the electrode modified with 10 mg of the prepared copolymers plasticized with TCP (electrode I). Under the optimized provision, the electrode I shows Nernstian slope of 19.9 ± 0.36 mV decade− 1 over the concentration range from 1.0 × 10− 6 to 1.0 × 10− 2 mol L− 1 with a detection limit of 1.0 × 10− 6 mol L− 1 and pH ranges from 3 to 8. The paste is enough stable for 37 days without any detected change in the potential. The proposed method is more potent in determination of Al(III) in both real water and pharmaceutical samples potentiometrically. The results obtained agreed with those obtained with spectrophotometer and inductive coupled plasma (ICP).