SQUARE-WAVE ANODIC-STRIPPING VOLTAMMETRY IN STATIONARY AND FLOWING SOLUTION - A COMPARATIVE-STUDY

A comparison has been made between square-wave anodic stripping voltam metry (SWASV) at a stationary, mercury thin-film electrode and at a wa ll-jet mercury thin-film electrode in flowing solution using cadmium(I I) and lead(II) as test species. Mercury thin films were prepared on g lassy carbon electrode substrates. The effects of square wave amplitud e and frequency on the peak current and peak potential in the determin ation step were studied, and these parameters optimized. Deposition ti me was varied, and the effect of flow rate in flowing solution investi gated. Practical detection limits were found to be 10(-8) mol l(-1) at stationary electrodes and 2 x 10(-9) mol l(-1) at wall-jet electrodes . It was found that SWASV gives good results in the presence and absen ce of dissolved oxygen for both analysis modes, which augurs well for its future application in dow systems, and particularly at wall-jet el ectrodes.