Publicação: Preconcentration and determination of mercury(II) at a chemically modified electrode containing 3-(2-thioimidazolyl)propyl silica gel
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Data
2005-11-01
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A mercury-sensitive chemically modified graphite paste electrode was constructed by incorporating modified silica gel into a conventional graphite paste electrode. The functional group attached to the (3-chloropropyl) silica gel surface was 2-mercaptoimidazole, giving a new product denoted by 3-(2-thioimidazolyl)propyl silica gel, which is able to complex mercury ions. Mercury was chemically adsorbed on the modified graphite paste electrode containing 3-(2-thioimidazolyl)propyl silica (TIPSG GPE) by immersion in a Hg(II) solution, and the resultant surface was characterized by cyclic and differential pulse anodic stripping voltammetry. One cathodic peak at 0.1 V and other anodic peak at 0.34 V were observed on scanning the potential from -0.1 to 0.8 V (0.01 M KNO3; ν = 2.0 mV s-1 νs. Ag/AgCl). The anodic peak at 0.34 V show an excellent sensitivity for Hg(II) ions in the presence of several foreign ions. A calibration graph covering the concentration range from 0.02 to 2 mg L-1 was obtained. The detection limit was estimated to be 5 μg L-1. The precision for six determinations of 0.05 and 0.26 mg L-1 Hg(II) was 3.0 and 2.5% (relative standard deviation), respectively. The method can be used to determine the concentration of mercury(II) in natural waters contaminated by this metal. 2005 © The Japan Society for Analytical Chemistry.
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2 imidazolidinethione, 2-mercaptoimidazole, cation, drug derivative, fresh water, graphite, imidazole derivative, mercaptoimidazole, mercury, sea water, silica gel, silicon dioxide, calibration, chemistry, electrochemistry, instrumentation, ion selective electrode, methodology, oxidation reduction reaction, pH, reproducibility, Calibration, Cations, Electrochemistry, Ethylenethiourea, Fresh Water, Graphite, Hydrogen-Ion Concentration, Imidazoles, Ion-Selective Electrodes, Mercury, Oxidation-Reduction, Reproducibility of Results, Seawater, Silicon Dioxide
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Inglês
Como citar
Analytical Sciences, v. 21, n. 11, p. 1359-1363, 2005.
