Tetrachlorophenylporphyrinato Manganese(III) Acetate as a New Ionophore for a Coated Triiodide Ion‐Selective Electrode

Abstract

AbstractA novel triiodide sensor based on (tetrachlorophenylporphyrinato) manganese(III) acetate is described. The electrode is prepared by incorporating the ionophores into plasticized PVC membrane, which is directly coated on the surface of a graphite electrode. The resulting electrode has a linear dynamic range between 1.0 × 10−1 and 7.9 ×10−6 M with a near‐Nernstian slope of −66.5 ± 1.0 mV per decade and a detection limit of 6.0 × 10−6 M. The influences of lipophilic additives on the response properties of the electrode were investigated. The proposed sensor revealed high selectivity for triiodide over a wide variety of other anions and could be used in a pH range 2–9. The electrode can be used for at least 3 months without any considerable divergence in potential. It was applied as indicator electrode in potentiometric titration of ascorbic acid and triiodide ions.