APPLICATION OF A MULTICHANNEL POTENTIOSTAT TO METAL-ION DETERMINATIONS IN FLOW-INJECTION ANALYSIS

A 4-channel potentiostat has been developed for use with an amperometr ic array and applied to the determination of a mixture of metal ions i n flow injection analysis (FIA). The use of an array facilitates the a cquisition of three dimensional electrochemical information in real-ti me (current vs. potential vs. time). The data acquired can be saved in ASCII format which facilitates post-run plotting of the 2- and 3-D vo ltammograms in Microsoft Excel. The results demonstrate the increased information content available with an amperometric array over fixed po tential electrodes. The ability to identify the individual species in mixed component injections, which is normally not possible with FIA wi thout a prior separation step has been demonstrated. Linear responses to injections of copper(II) ions in the concentration range 500 ppm to 100 ppb were obtained.