Analytical Sciences

Abstract − Analytical Sciences, 14(1), 157 (1998).

A Liquid/Liquid-Type Heteropolyanion Reference Electrode for Ion-Transfer Voltammetry
Toshiyuki OSAKAI and KazuhiroMUTO
Department of Chemistry,Faculty of Science, Kobe University, Nada, Kobe 657, Japan
A new liquid/liquid-type reference electrode forion-transfer voltammetry with the nitrobenzene (NB)/water (W)interface has been developed. This reference electrode is expressed asPt/1.8 mM a-[SiMo12O40]4- +0.2 mM a-[SiMo V 2Mo12O40]4- + 0.1 M H2SO4 (W)/0.3 mM a-[SiMo12O40]4-+ 0.02 M tetrahexylammonium tetraphenylborate (NB).The Galvani potential difference between the reference NB/W interface isdetermined virtually by the distributionequilibrium of the heteropolyanion (a-[SiMo12O40]4- ), whereas the Ptelectrode potential is determined by the redoxequilibrium of the heteropolyanion couple. With this reference electrode, apotential window of about 0.4 V is availablein a fairly negative potential region, where the transfer of hydrophilicinorganic anions (Br - , I- , SCN -, NO3 - , andClO4 - )can be observed voltammetrically. (Keywords: Reference electrode, ion-transfer voltammetry,12-molybdosilicate, nitrobenzene/water interface)