Potentiometric Behavior of Co(II)-Meso-tetraarylporphyrin Derivatives as Ionophores in Anion-Selective Electrodes. Cross Sensitivity Studies

Abstract

Co(II)-meso-tetraarylporphyrin derivatives were studied as ionophores for polymeric membrane sensors for anions, and the cross-sensitivity of sensors were evaluated. It was found that the electrode displays a low cross-sensitivity and high selectivity to iodide ion. The iodide electrode exhibits a Nernstian response over a concentration range of 1.2 × 10⁻⁵ M–1.0 × 10⁻² M with a detection limit of 9.0 × 10⁻⁶ M for the polymeric membrane electrode (PME) and 8.0 × 10⁻⁶ M–2.0 × 10⁻² M with a detection limit of 7.5 × 10⁻⁶ M for the coated glassy carbon electrode (CGCE) in the pH range 3.0–7.0. The electrode possesses a fast response time, a satisfactory reproducibility and a good lifetime.

Keywords:

• Anion-selective electrodes
• Carboxylated-PVC
• Co(II)-meso-tetraarylporphyrin
• Cross sensitivity
• Iodide sensor

Acknowledgments

The support of this work by a research grant (no. 84123/17) from Iran National Science Foundation (INSF) is gratefully acknowledged.