Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1245392 | Talanta | 2008 | 7 Pages |
Abstract
Central composite design (CCD) and response surface methodology (RSM) were developed as experimental strategies for modeling and optimization of the influence of some variables on the performance of a new PVC membrane triiodide ion-selective electrode. This triiodide sensor is based on triiodide-clozapine ion-pair complexation. PVC, plasticizers, ion-pair amounts and pH were investigated as four variables to build a model to achieve the best Nernstian slope (59.9 mV) as response. The electrode is prepared by incorporating the ion-exchanger in PVC matrix plasticized with 2-nitrophenyl octal ether, which is directly coated on the surface of a graphite electrode. The influence of foreign ions on the electrode performance was also investigated. The optimized membranes demonstrate Nernstian response for triiodide ions over a wide linear range from 5.0 Ã 10â6 to 1.0 Ã 10â2 mol Lâ1 with a limit of detection 2.0 Ã 10â6 mol Lâ1 at 25 °C. The electrodes could be used over a wide pH range 4-8, and have the advantages of easy to prepare, good selectivity and fast response time, long lifetime (over 3 months) and small interferences from hydrogen ion. The proposed electrode was successfully used as indicator electrode in potentiometric titration of triiodide ions and ascorbic acid.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Khalil Farhadi, Morteza Bahram, Donya Shokatynia, Floria Salehiyan,