The applicability of gold microelectrode of 25 mu m diameter for electrochemical determination of trace copper ions (Cu(2+)) in water samples by anodic stripping voltammetry (ASV) has been demonstrated. The analysis of Cu(2+) at gold microelectrode includes two steps. Cu(2+) ions are firstly reduced and accumulated on the microelectrode surface during an accumulation step, then oxidized during the positive potential sweep. Due to the rapid mass transporting and low background current of gold microelectrode, low detection limit (0.3 nM) and wide linear range (1.0-90 nM) can be obtained. The practical application of gold microelectrode was verified by determination of trace level of Cu(2+) in tap water, lake water and commercial drinking water samples
