Upstream microelectrodialysis for heavy metals detection on boron doped diamond

Paper shows the development of a microelectrodialyser with a 6 μL active volume with the aim to miniaturized a total analysis system (μTAS) using microfluidic chips for heavy metals analysis. Microsystem was fabricated with ion-exchange membranes to define concentration and dilution compartments and platinum wires as electrodes in order to pre-concentrate and pre-treat heavy metals in water solution. After 200 min electrodialysis at 15 μL min−1, a concentration factor up to 120 has been obtained in the case of the treatment of a Pb(NO3)2 solution. With the aim to combine a microelectrodialyser with a mercury free electrochemical detection of heavy metals, boron doped diamond (BDD) film performances as working electrode were studied for Pb2+ analysis by SWASV. A linear detection from 20 ppb to 100 ppb of lead has proved the stability of the BDD electrode. Concentration range is compatible with the electrodialyser channel outlet allowing in associated both presented systems to built an innovative lab-on-a chip microsystem to environmental analysis.