ELECTROCHEMICAL DETERMINATION OF TRACE AMOUNTS OF GOLD(III) BY ANODIC-STRIPPING VOLTAMMETRY USING A CHEMICALLY-MODIFIED ELECTRODE

An electrochemically pretreated glassy carbon electrode (GCE) modified with an aza crown ether, 8,9,17,18-dibenzo-1,7-dioxa-10,13,16-triazacyclooctadecane (DDTC), has been used for the very sensitive and selective analysis of trace amounts of gold(III). A detection limit of 4.2 x 10(-10) M was obtained by applying anodic stripping voltammetry. The parameters that affect the sensitivity and possible interferences by other ions have been examined in detail. The modified electrodes exhibit high stability and, therefore, have been used repeatedly without mechanical regeneration. Finally, the method has been successfully applied to determine gold traces in a geological sample.