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Ion‐exchange voltammetry of trace mercury( II ) at glassy carbon electrodes coated with a cationic polypyrrole derivative. Application to pore‐waters analysis
Author(s) -
Ugo Paolo,
Sperni Laura,
Moretto Ligia M.
Publication year - 1997
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.1140091504
Subject(s) - polypyrrole , mercury (programming language) , glassy carbon , inorganic chemistry , differential pulse voltammetry , chemistry , ion exchange , voltammetry , electrochemistry , aqueous solution , electrode , detection limit , chloride , acetonitrile , cyclic voltammetry , ion , organic chemistry , chromatography , computer science , programming language
Glassy carbon electrodes modified with coatings of poly‐[1‐methyl‐3‐(pyrrol‐1‐ylmethyl)pyridinium], poly‐MPP, were prepared by electrochemical oxidation of the suitable monomer in acetonitrile solutions. The anion exchange properties of the coated electrode were exploited in aqueous solutions for preconcentrating and detecting the anionic complex HgCl 4 2− , which is the prevailing inorganic Hg II species in seawater and other chloride media. The partition coefficients for the ion‐exchange equilibrium involved were calculated from voltammetric data and compared with those obtained at electrodes coated with Tosflex, a perfluorinated anion exchanger, and poly(vinylpyridine). The selectivity of the poly‐MPP coated electrodes towards the rejection of copper interference was also studied. The optimization of experimental conditions allowed the development of a differential pulse voltammetric method for the determination of submicromolar mercury concentrations with a detection limit of 0.1 nM. The method was applied to the analysis of mercury in the pore‐waters of tidal sediments of the Lagoon of Venice (Italy), determining Hg II concentration values in the 70–80 nM range.