Different species of trace heavy metals (HMs) in seawater samples were simultaneously analyzed by anodic stripping voltammetric method, an analytical technique that does not require sample pre-concentration or the addition of reagents. The effects of the crucial parameters, deposition potential and time, on the determination of HMs were investigated. Concentrations of the total dissolved, dissolved active, and dissolved inert HMs were obtained through different analysis processes. The three species of Cu, Pb, Cd and Zn in seawater samples collected in different locations across Sishili Bay, North Yellow Sea, China were studied. The relative concentration of the dissolved active Cu, Pb, Cd and Zn in the total dissolved concentrations is 59.0%, 69.6%, 87.3% and 84.1%, respectively. The concentrations of different HMs species in Sishili Bay could be affected by the discharged effluent, sea current, and uptake of marine organism.

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A portable electrophoresis device based on the SU-8/Pyrex microfluidic chip with integrated three 100 μm platinum (Pt) thin-film electrodes (working, reference, and auxiliary) was adapted for the analysis of silver nanoparticles (AgNPs). The microfluidic platform includes the main electrophoresis instrument, reusable holder, and microfluidic chip with integrated Pt electrodes. The electrochemical oxidation behaviours of AgNPs on Pt thin-film electrode were investigated by using cyclic voltammetry, while the electrophoresis behaviours of AgNPs were studied on the 'Lab-on-a-chip' platform. The influences of parameters including running buffer, separation voltage, and detection potential on the electrophoresis behaviours of AgNPs were all investigated. The results showed that AgNPs could be oxidised at 0.2-0.4 V [phosphate buffer solution buffer, pH 7.0] on the Pt thin-film electrode. The peak current enhanced with the increase of separation voltage, while the retention time decreased. The peak current varied with the detection potential and reached the highest value at 0.4 V. This microfluidic platform could be a fast and portable detection system for the analysis of total AgNPs.