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Carbon paste electrode and medium‐exchange procedure in adsorptive cathodic stripping voltammetry of selenium(IV)
Author(s) -
Ferri Tommaso,
Guidi Francesco,
Morabito Roberto
Publication year - 1994
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.1140061129
Subject(s) - cathodic stripping voltammetry , detection limit , stripping (fiber) , chemistry , linear sweep voltammetry , anodic stripping voltammetry , adsorptive stripping voltammetry , voltammetry , electrode , carbon paste electrode , cathodic protection , analytical chemistry (journal) , cyclic voltammetry , electrochemistry , inorganic chemistry , chromatography , materials science , composite material
Abstract An adsorptive cathodic stripping voltammetric method for the determination of Se(IV) is described. The method is based on the detection of the piazselenol complex formed by Se(IV) with 2,3‐diamino naphthalene (2,3 DAN) at pH 2 (0.01 mol L −1 HC1 + 0.1 mol L −1 KC1). The method is based on a medium‐exchange scheme and a carbon paste electrode (CPE). The preconcentration step is carried out at open circuit, and then the complex is stripped out by linear sweep voltammetry (LSV) after medium exchange (0.1 mol L −1 HNO 2 + 0.1 mol L −1 KNO 3 where the working electrode is transferred). The method is characterized by a precision better than 8% and a limit of quantitation (10 times the standard deviation of the blank) of 1.25 × 10 −7 mol L −1 (for 20 minutes of preconcentration time). The use of CPE coupled with the medium‐exchange scheme reduces the interferences (especially by different classes of surfactants) and improves the selectivity (much better than in the usual cathodic stripping voltammetry on mercury).