Authors | _ |
---|---|
Journal | Analytical Chemistry |
Page number | 2591-2595 |
Serial number | 74 |
Volume number | 11 |
Paper Type | Full Paper |
Published At | 2002 |
Journal Grade | ISI |
Journal Type | Typographic |
Journal Country | Iran, Islamic Republic Of |
Journal Index | ISI،JCR،Scopus |
Abstract
Three new electrodes were prepared by incorporating two different charge-transfer complexes and amino crown ether into plasticized PVC membranes. The electrodes showed Nernstian response to triiodide ion over the activity range from 1.0 × 10-5 to 1.0 × 10-1 mol‚L-1 with detection limits at ∼1.0 × 10- 6 mol‚L-1. The resulting electrodes have fast response times (20-30 s) and good stabilities (4 months) and can be used over a wide pH range of 2.5-9.0. The proposed electrodes exhibit anti-Hofmeister behavior with excellent selectivity toward triiodide ion against a wide range of common interferences. Comparative study suggests that amino (aza) crown ether alone or in the form of a charge-transfer complex with iodine, as an ionophore in a PVC liquid membrane, is sensitive to triiodide ion. The electrodes were used as indicator electrodes in potentiometric titration of triiodide ion against thiosulfate ion.
tags: ion-pair; crown ether; triiodide; potentiometry