Application of the interdigitated array microelectrodes in trace determination of selenium in water samples

A method applying an interdigitated array (IDA) microelectrode is proposed for the trace determination of species for which stripping analysis is disa bled by the formation of multiple peaks during electrochemical dissolution of the deposit. Independent polarization of both (IDA) microelectrode array s was applied. The time dependence of the reduction current of the deposit dissolved in the diffusion layer of the IDA microelectrode is used for thr evaluation of the concentration. As the I-eduction current is registered at the segment polarized by a constant potential, it is practically free of t he undesired capacity component. A method of multiple standard additions wa s used for the quantification. The method was tested using synthetic sample s containing Se at the trace level required by the Slovak Republic regulati ons, and was next used for the determination of Se in Lap and environmental water.