Highly Thiocyanate-Selective PVC Membrane Electrode Based on Lipophilic Ferrocene Derivative

✍ Scribed by Jianyuan Dai; Ruo Yuan; Yaqin Chai; Lanxiang An; Xia Zhong; Yan Liu; Dianping Tang

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 72 KB
• Volume: 17
• Category: Article
• ISSN: 1040-0397
• DOI: 10.1002/elan.200503313

✦ Synopsis

Abstract

A novel anion‐selective PVC membrane electrode based on bis‐[(3‐ferrocenyl)‐(2‐crotonic acid)] copper(II) complex [Cu(II)‐BFCA] as neutral carrier is described, which demonstrates excellent potentiometric response characteristics toward thiocyanate ion and anti‐Hofmeister selectivity sequence in following order: SCN^−^>I^−^>ClO$\rm{ {_{4}^{-}}}$>Sal^−^>Br^−^>NO$\rm{ {_{3}^{-}}}$>Cl^−^≈NO$\rm{ {_{2}^{-}}}$>SO$\rm{ {_{3}^{2-}}}$>SO$\rm{ {_{4}^{2-}}}$. The electrode shows a near‐Nernstian response for thiocyanate ion in a wide range of 9.0×10^−7^–1.0×10^−1^ M with a detection limit 6.8×10^−7^ M and a slope of −59.1 mV/decade in pH 5.0 of phosphate buffer solution at 20 °C. The influences of lipophilic cationic and anionic additives on the response properties of the electrode were investigated. High sensitivity and wide linear dynamic range were observed for the electrode in the presence of hexadecyltrimethylammoniumborate (HTAB) as a lipophilic cationic additive. The electrode was successfully applied to the determination of thiocyanate ion in waste water and human saliva.