PVC-based Cu(II)-Schiff base complex membrane coated graphite electrode for the determination of the triiodide ion

摘要

A triiodide-selective electrode based on copper (II)-Schiff base complex as a membrane carrier is proposed. The electrode was prepared by incorporating the carrier into a plasticized polyvinylchloride (PVC) membrane and was directly coated on the surface of a graphite electrode. The obtained electrode showed a near Nernstian slope of 57.0 +/- 0.4 mV/decade to I-3(-) ions over an activity range of 1.0 x 10(-5)-1.0 x 10(-1) M with a limit of detection of 4.8 x 10(-6) M. The response time of the electrode was fast (5 s) and the electrode could be used for about 2 months without considerable divergence in response. The potentiometric selectivity coefficients were evaluated and displayed anti-Hofmeister behavior. The electrode was used as an indicator electrode in the potentiometric titration of the triiodide ion and in the determination of ascorbic acid in vitamin C tablets.