Titre du document / Document title

Surface studies of the jalpaite-based copper(II) ion-selective electrode membrane in seawater

Auteur(s) / Author(s)

DE MARCO R. ⁽¹⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ School of Applied Chemistry, Curtin University of Technology, G.P.O. Box U 1987, Perth, W.A. 6001, AUSTRALIE

Résumé / Abstract

Copyright (c) 1996 Elsevier Science B.V. All rights reserved. Ageing of the jalpaite Cu(II) ion-selective electrode (ISE) membrane in saline solutions and seawater has been studied using X-ray photoelectron spectroscopy (XPS), and it is shown that the membrane surface composition is altered after exposure to these media. XPS evidence shows that the change in membrane surface composition in a saline Cu(II) ion buffer involves the transformation of jalpaite (i.e. Ag_1.5Cu_0.5S) to a mixture comprising copper-deficient sulfide (i.e. Ag_1.5Cu_0.5−2xS_1−x) and AgCl. A similar process takes place in seawater with the exception that AgI is also formed on the membrane surface. The variation in membrane surface composition in saline solution and seawater has been linked to the electrochemical behaviour of the Cu(II) ISE. XPS analysis of membranes treated in seawater has identified the carboxylic acid-based organic substances of seawater (i.e. humic and fulvic acids) on the surface of the jalpaite membrane. In seawater and saline Cu(II) ion buffers, the chloride induced poisoning of the jalpaite membrane is suppressed through the adsorption of surfactant-like ionic forms of the organic ligands onto the membrane surface. The findings of this work have important ramifications for the application of the jalpaite Cu(II) ISE in studies of Cu(II) complexation in seawater.

Revue / Journal Title

Marine chemistry   ISSN 0304-4203   CODEN MRCHBD 

Source / Source

1996, vol. 55, n^o3-4, pp. 389-398

Langue / Language

Anglais

Editeur / Publisher

Elsevier, Amsterdam, PAYS-BAS  (1972) (Revue)

Mots-clés anglais / English Keywords

experimental studies ; X-ray spectroscopy ; jalpaite ; copper ; saline composition ; solution ; analysis ; sea water ; hydrochemistry ; X-ray analysis ; electrochemical properties ; humic acids ; fulvic acids ; potentiometry ; sulfides ;

Mots-clés français / French Keywords

Etude expérimentale ; Spectrométrie RX ; Jalpaite ; Cuivre ; Composition saline ; Solution ; Analyse ; Eau mer ; Hydrochimie ; Analyse RX ; Propriété électrochimique ; Acide humique ; Acide fulvique ; Potentiométrie ; Sulfure ;

Mots-clés espagnols / Spanish Keywords

Espectrometría RX ; Jalpaita ; Cobre ; Composición salina ; Agua mar ; Hidroquímica ; Análisis RX ; Propiedad electroquímica ; Acido húmico ; Acido fúlvico ; Potenciometría ; Sulfuro ;

Localisation / Location

INIST-CNRS, Cote INIST : 15979, 35400006137138.0028