PRECONCENTRATION AND VOLTAMMETRIC MEASUREMENT OF SILVER(I) WITH A CARBON-PASTE ELECTRODE MODIFIED WITH 2,9-DICHLORO-1,10-PHENANTHROLINE-SURFACTANT

A chemically modified carbon paste electrode was prepared by incorporating appropriate amounts of 2,9-dichloro-1,10-phenanthroline and surfactant directly in a paste mixture. The electrode was able to bind silver ions chemically, and gave a better voltammetric response for silver than did ordinary carbon paste electrodes. The response was characterized with respect to paste composition, preconcentration time, silver ion concentration, reproducibility, possible interferences and other variables. The method showed good linearly for 8 x 10(-10)-5 x 10(-7) mol l(-1) silver(I) in nitric acid medium. The performance of the electrode was verified by the determination of silver(I) in waste water.