Improved sensitivity and reproducibility in electrochemical detection of trace mercury (II) by bromide ion & electrochemical oxidation.

Author(s) Zou, Y.; Zhang, Y.; Xie, Z.; Luo, S.; Zeng, Y.; Chen, Q.; Liu, G.; Tian, Z.
Journal Talanta
Date Published 2019 Oct 01
Abstract

Nanostructured gold electrodes have been widely used for electrochemical trace analysis of Hg because Hg has superior specificity for the formation of gold amalgam. However, it is still very challenging to achieve both high sensitivity and reproducibility, especially for real environmental water samples due to surface poisoning by organic residues. In this work, we developed two strategies for addressing these challenges. First, we added NaBr (with a final concentration of 0.01 M) to the analytes; this enhanced the sensitivity by two orders of magnitude and improved the reproducibility to be better than RSD <15% because of the synergetic interaction of Br with Hg and gold at the interface. Second, we developed a pre-oxidation method using a glassy carbon electrode to remove organic residue from the analyte before Hg analysis. The combination of these two approaches results in an efficient, reliable, and fast electrochemical detection technique for on-site trace analysis of Hg that is in concentrations lower than that required by WHO for drinking water.

DOI 10.1016/j.talanta.2019.05.072
ISSN 1873-3573
Citation Zou Y, Zhang Y, Xie Z, Luo S, Zeng Y, Chen Q, et al. Improved sensitivity and reproducibility in electrochemical detection of trace mercury (II) by bromide ion & electrochemical oxidation. Talanta. 2019;203:186-193.

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