Coated-Wire Silver Ion-Selective Electrode Based on Silver Complex of Cyclam

A coated-wire ion-selective electrode (ISE) based on cyclam (1,4,8,11-tetraazacyclotetradecane) as a neutral carrier in a polyvinyl chloride (PVC) matrix was fabricated for the determination of Ag(I) ions. The coated-wire ISE exhibited a linear Nernstian response over the range 1 × 10-1 to 1 × 10-7 M with a slope of 59 ± 2 mV per decade change and a detection limit of 5 × 10-8 M. The ISE shows a greater preference for Ag over other cations with good precision. The electrode was selective towards Ag(I) ions in the presence of 13 different metal ions tested. The selectivity coefficients (Kij) were determined for Na(I), K(I), Mg(II), Ca(II), Ba(II), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Pb(II) and Hg(II). The selectivity coefficients of these cations are in the range of 10-4 to 10-2. This ISE was used for the determination of free silver and total silver in electroplating bath solutions, additives and brighteners.