Anatytzca Chmtca Acta, 273 (1993) 229-236 Elsevler Science Pubhshers B V , Amsterdam 229 Ion-exchange voltammetry of copper ions in chloride media at glassy carbon electrodes modified with polycationic ionomers Paolo Ugo, Ligla Maria Moretto and Glan Antonio Mazzocchm Department of Physical Chenustry, Unrvemty of Verne, Calle Larga S Marta 2137, I-30123 Vemce (Italy) (Recewed 1st June 1992) Perfluonnated polycatlomc polymers (Tosflex) were appbed for preparmg polymer-modtied electrodes able to preconcentrate amomc complexes of Cu+ electrogenerated m situ at the electrode/polymer Interface by reducmg Cu*+ solutions m the presence of chlonde Ions The species Incorporated mto the polymenc coating, namely C&l;, was detected by a sultable lmear sweep voltammetnc reoxldatlon scan The dependence of the reoxldatlon peak current on experunental parameters such as amount of modtier, electrogeneratlon-preconcentratlon time and solution concentrations of Cu’+ and Cl- was studled The posslbd~ty of applymg Tosflex-moddied electrodes to copper speclatlon studies was also exammed In partrcular, the Influence on the ion-exchange voltammetic responses of some ammo aads such as hlstldme, glycme and glutanuc acid whsh, at the pH employed m this study, carry positive, neutral and negative lomc charges, respectively, IS discussed Some of the advantages and lmutatlons of Tosflex-modified electrodes compared with Nafion-coated electrodes and the hangmg mercury drop electrode are cntlcally evaluated Keywords Copper, Glassy carbon electrodes, Polycatlomc monomer coatmgs, Speclatlon The use of ion-exchanger-coated electrodes to preconcentrate and detect electroactlve species IS a rapldly growmg field which has gwen rise to the technique of ion-exchange voltammetry [ 11 Cation-exchange voltammetry usually employs electrodes modlfied with Nafion, a perfluormated monomer whose popularity is mainly due to the ease with which stable modtiled electrodes can be prepared from commercially available solutions Correspondence to P Ugo, Department of Physical Chem- Istry, Umverslty of Vemce, Calle Larga S Marta 2137, I-30123 Vemce (Italy) of the polymer Recently, Ion-exchange voltam- metry at Nafion-coated electrodes has been ap- plied for detecting electroactlve catlons, such as blologrcally actlve orgamcs [2-41 or f-element cations [5-71, for which classical anodlc stnppmg methods are not applicable Concemmg amon exchangers, smce the plo- neermg work of Oyama and Anson [81, the most often studled polycatlomc modifier IS polyvmyl- pyrldme which, however, presents some problems such as non-Ideal permselectlvlty 19,103 and the need for stabtllzatlon by chemical cross-lmkmg zyxwv [W21 0003-2670/93/$06 00 0 1993 - Elsevler Science Pubhshers B V All rights reserved