Analysis of Heavy Metal Ions in Real Samples using a Concentrator Device with a Super-Hydrophobic Surface

Heavy metal ions in soil samples were analyzed by a novel method based on evaporative concentration. The detector chip had a microelectrode array as a working electrode and a Ag/AgCl reference electrode surrounded by a super-hydrophobic layer formed with polytetrafluoroethylene (PTFE) beads. A sample droplet formed on the electrode area was shrunk to concentrate the solution. Cd2+, Pb2+, and As3+ ions were analyzed by square wave anodic stripping voltammetry. By combining a protective layer and wet sample digestion, the heavy metal ions in soil samples could be analyzed. Correlation coefficients between the values obtained by this method and those by a conventional method was 0.982 (Pb2+), 0.969 (Cd2+), and 0.936 (As3+).