Selective and Non-Selective Determination ofHeavy Metal Ions in Flowing Solutions by Fast Stripping Cyclic Voltammetry

Abstract

A simple and fast stripping voltammetric detection method has been designed for selective and non-selective measurements of heavy metal ions in a flow-injection system. A special computer numerical method is introduced for calculating the analyte signal and noise reduction, where the signal is calculated based on the partial and total charge exchange at electrode surface. For a selective determination, the currents are integrated in the range of the oxidation and reduction of the analyte. For non-selective measurements, the integration range is set for the whole potential scan range (including oxidation and reduction of the Au surface). The time for stripping has been shown to be less than 300 ms. The main advantages of the detection method are as follows: first, removal of oxygen from the measured solution is not required; second, it is sufficiently fast for the determination of heavy metal ions in various chromatographic analysis methods. The limit of detection for tested ions was between 3 × 10 -9 and 6 × 10 -10 M, and the relative standard deviation at 50 ppb Pb 2+ was 4.7% for 10 runs.

Electroanalytical Determination of Cadmium(II) and Lead(II) Using an in-situ Bismuth Film Modified Edge Plane Pyrolytic Graphite Electrode

“…edge plane sites are likely responsible. It is worth mentioning that some of the nonmercury based electrodes used for the detection of cadmium(II) and lead(II), as detailed in Table 3, suffer from complexity in manufacturing the electrodes, 14 instrumentation 45,46 and/or modification process or synthesis of modifiers such as complexing agents. 47,48 Compared to these requirements, the handling of our proposed electrode is much more simple and can be easily used in every electrochemical lab.…”