DETERMINATION OF GOLD BY ANODIC-STRIPPING VOLTAMMETRY WITH CARBON-FIBER ULTRAMICROELECTRODES

Carbon fiber ultramicroelectrodes have been used in anodic stripping v oltammetry (ASV) of trace gold. The advantageous characteristics of ul tramicroelectrodes combined with ASV resulted in a fast, selective, se nsitive and reproducible method. An electrochemical pretreatment was n ecessary for analytical determinations. The combination of supporting electrolyte (HCl 0.1 M) and electrodeposition potential (0.0 V) gave a high selectivity. A calibration plot from 1.00 x 10(-8) M to 1.60 x 1 0(-6) M (r = 0.9994) was achieved with a detection limit of 5.94 x 10( -9) M and a relative standard deviation (RSD) of 2.87 % at 3.0 x 10(-7 ) M. Ag-I, Cu-II, Pb-II and Hg-II metals in the concentration of 1.00 x 10(-6) M were nor found to interfere with the ASV of gold (3.00 x 10 (-7) M) when carried out under optimum conditions. The procedure was a pplied to the determination of gold in two tap water synthetic samples .