Disposable screen-printed electrodes (SPE) mercury-free for the lead detection

Strategies to modify screen-printed electrodes (SPE) for lead determination are reported. Dithizone was mixed with graphite ink to obtain a modified screen-printed strip to detect ppb levels of lead(II) (detection limit 12 microg/L) using square wave anodic stripping voltammetry (SWASV). In addition, screen-printed electrodes were also modified by casting a few microL of a Nafion solution onto the working electrode surface. In this case, ppb levels of lead were detected (detection limit 15 microg/l), using potentiometric stripping analysis (PSA). The addition of an ionophore to Nafion polymer was also investigated, but this did not yield a significant improvement.