Revising Flow-Through Cells for Amperometric and Voltammetric Detections Using Stationary Mercury and Bismuth Screen Printed Electrodes

Heavy metals attract a rising attention in environmental studies due to their increasing release by human activities and acute toxicity. In situ analytical methods are needed to minimize current uncertainties caused by the transport and conservation of samples. Here, we present two multisyringe flow analysis (MSFIA) procedures to determine Tl(I) Pb(II), In(III), and Cd(II) using four homemade flow cells for amperometric and anodic stripping voltammetric detection using a  stationary mercury electrode (SMDE), and another two using bismuth screen printed electrodes for Cd(II) and Pb(II). In all cases, a differential pulse polarographic system has been used. The control of the whole process has been carried out with a personal computer and the AutoAnalysis program. The Cd determination in drinking water has been assessed using the anodic stripping variant, which has allowed carrying out analyses with very low sample consumption, unable to be manipulated using batch methods. The detection limit for a sample of ۲۰۰ μL was of ۲.۳ µg L-۱, which in terms of absolute analyte amount corresponds to ۴۵۰ picograms. The use of screen-printed electrodes in MSFIA, together with the small volume of the flow cell and the reduced surface area of the solid phase electrode (SPE) have considerably reduced the volume of reagents and samples to be used. The Bi use is one of the most important advantages of this system, since it is a recognized substitute for Hg, and its impact on the environment is much lower due to its reduced toxicity.

کلیدواژه ها:

Multisyringe Flow injection ، Analysis (MSFIA) ، anodic stripping voltammetry ، Amperometric Detection ، Differential pulse voltammetry ، Stationary mercury electrodes ، Bismuth screen printed ، Electrodes