Talanta 2013-09-30

Solid-contact Hg(II)-selective electrode based on a carbon-epoxy composite containing a new dithiophosphate-based ionophore.

J Juarez-Gomez, F Perez-Garcia, M T Ramirez-Silva, A Rojas-Hernandez, C A Galan-Vidal, M E Paez-Hernandez

Index: Talanta 114 , 235-42, (2013)

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Abstract

The experimental results herein concern a novel ion-selective electrode manufactured with an inner solid contact based on a new ligand O,O'-(2,2'-biphenylene)dithiophosphate pentyl (PenDTF). This electrode displays high selectivity toward the Hg(II) ion even in the presence of different divalent ions. The electrode also exhibited a good Nernstian response to Hg(II) (33.7±1.0 mV decade(-1)) over an ample concentration range (5.3×10(-7)-1.0×10(-2) mol L(-1)), with a detection limit of (6.1±1.7)×10(-7) mol L(-1). As a result of design, the electrode can be used for many experiments, simply renewing its contact surface with emery paper, without giving rise to a significant response deviation, exhibiting a variation coefficient of 3%, capable of being tested within the 0-5 pH interval. The electrode was used satisfactorily as indicating electrode during the potentiometric titration of Hg(II) ions with EDTA.Copyright © 2013 Elsevier B.V. All rights reserved.