Highly selective and sensitive determination of silver(I) at a poly(8-mercaptoquinoline) film modified glassy carbon electrode

Abstract

8-Mercaptoquinoline was found to be electropolymerizable by a cathodic process at a glassy carbon electrode. The resulting modified electrode could be used for selective open circuit preconcentration of Ag(I). This, followed by medium exchange and anodic stripping analysis provided a highly selective and sensitive method for Ag(I) determination. Optimized procedures for both batch and flow analysis were developed. For batch determination, a detection limit of 2.7 × 10-11 M Ag(I) was achieved (S/N = 3, 10 min preconcentration). The relative standard deviations (n = 11) for 1.00 × 10-9 M and 2.00 × 10-10 M Ag(I) were 2.60% and 4.74%, respectively. Similar results were observed for flow analysis. Of 44 selected potential interferents studied, only Au(III) interfered.