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Carbon paste electrodes plated with a gold film for the voltammetric determination of mercury( II )
Author(s) -
Švancara Ivan,
Matoušek Milan,
Sikora Eugen,
Schachl Klemens,
Kalcher Kurt,
Vytřas Karel
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.1140091105
Subject(s) - mercury (programming language) , electrolyte , detection limit , supporting electrolyte , anodic stripping voltammetry , chemistry , analytical chemistry (journal) , electrode , ion , voltammetry , electrochemistry , nuclear chemistry , chromatography , organic chemistry , computer science , programming language
Carbon pastes of different compositions were tested as supports for gold film electrodes. A paste containing highly‐viscous silicone oil as a binder was found the most suitable. Experimental conditions were optimized in order to develop a differential pulse anodic stripping voltammetric method for the determination of mercury in water samples. In a supporting electrolyte containing HNO 3 (0.1 mol/L), (KCl 0.02 mol/L) and tetrachloroaurate(III) for in situ plating with a gold film, the response of Hg was found to be linear in a concentration range from 1 × 10 −9 up to 2.5 × 10 −7 mol/L (0.2–50 μg/L; accumulation potential +0.2V (vs. Ag/AgCl); accumulation time 30 s–5 min) with a detection limit of about 2.5 × 10 −10 mol/L (50 ng/L) after accumulating for 30 min. Reliability of the method depended mainly on the concentration of Au III in the electrolyte which had to be chosen adequately, with respect to the concentration level of Hg II in the sample. Interferences from some ions with the determination of mercury were also studied. The method was tested on both model and real samples and the results agreed well with those obtained by reference determinations.