Selective extraction and voltammetric determination of gold at a chemically modified carbon paste electrode

Abstract

A sensitive chemically modified electrode for measuring gold by differential-pulse voltammetry is described. The electrode is prepared by dissolving triisooctylamine in carbon paste. Because of the selective extraction of gold, most of the common metal ions do not interfere with the stripping voltammetric measurements. The electrode was used to determine gold in authentic mineral samples without pre-isolation. The calibration plots are linear over the concentration range 0.1–10 µg ml^–1 and the detection limit was found to be 0.03 µg ml^–1 after a 15 min accumulation period. The preparation and electrochemical properties of the electrode were studied and the mechanism of the accumulation of gold at the modified electrode is discussed.