Integrated isotachophoresis in a miniaturised format for the separation of heavy metal cations

A method allowing the determination of heavy metal cations using miniaturised isotachophoresis has been developed. Separations were performed using a chip milled from poly(methyl methacrylate) with integrated platinum wire conductivity detection electrodes. The use of miniaturised separations devices is particularly appropriate for analysis of toxic species, as both the volume of sample required and the volume of waste produced are reduced. In this work, particular attention was paid to the determination of cadmium(II) ions. The method developed allowed cadmium(II) to be determined in the presence of other common metal cations including calcium, manganese(II), cobalt(II), zinc(II), nickel(II) and lead(II). A limit of detection for cadmium(II) was calculated to be 9 x 10-6 M.