Deposition and stripping at heated microelectrodes. Arsenic(V) at a gold electrode

Hot-wire electrochemistry can be a valuable aid in stripping analysis at solid electrodes. Deposition as well as stripping can be done with increased temperature at remote places, leaving the bulk solution unaffected. As an example, arsenic(V) traces were deposited directly without prior reduction at a heated 25 mu m gold electrode. Deposition was followed by anodic stripping. Presence of gold(III) ions had a positive effect. The detection limit was enhanced by a factor of 14 when going from 22 degrees C to 60 degrees C. The effects are explained by assuming that inhibited chemical reactions are activated and that transport processes inside and outside the electrode are accelerated. (C) 1998 Elsevier Science Ltd. All rights reserved.