Carbon composition PVC based membrane in a highly selective and sensitive coated wire electrode for silver ion

The utility of carbon as a new component in a highly selective and sensitive coated wire electrode (CWE) for silver ion using 2-[(2-{2-[(2-carboxyphenyl)sulfanyl]ethoxy}ethyl)sulfanyl] benzoic acid as ionophore is demonstrated. This CWE exhibits a good Nernstian slope of 59.0+/-1 mV per decade in a wide linear concentration range of 2.0 x 10(-8) to 1.0 X 10(-2) M for AgNO3. The detection limit of this electrode is 1.2 x 10(-8) M of AgNO3. This sensor has a short response time of about 10s and could be used in a pH range of 2.5-8.7. High selectivity was obtained over seventeen various metal ions. The electrode is reproducible and stable for a period of two months. The proposed electrode has been used as an indicator electrode in potentiometric titration. This CWE was successfully applied in determination of silver in sulphadiazine cream and in fruit juice matrixes. (C) 2004 Elsevier B.V. All rights reserved.