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

8-Mercaptoquinoline was found to be electropolymerizable by a cathodic proc ess 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 selectiv e and sensitive method for Ag(I) determination. Optimized procedures for bo th batch and flow analysis were developed. For batch determination, a detec tion limit of 2.7 x 10(-11) M Ag(I) was achieved (S/N = 3, 10 min preconcen tration). The relative standard deviations (n = 11) for 1.00 x 10(-9) M and 2.00 x 10(-10) M Ag(I) were 2.60 % and 4.74 %, respectively. Similar resul ts were observed for flow analysis. Of 44 selected potential interferents s tudied, only Au(III) interfered.