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A graphite silver( I ) hexacyanoferrate( III ) composite electrode for the determination of iron ( III ) ions
Author(s) -
Kahlert Heike,
Scholz Fritz
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.1140091211
Subject(s) - prussian blue , graphite , ion , reagent , electrode , inorganic chemistry , chemistry , differential pulse voltammetry , voltammetry , calibration curve , cyclic voltammetry , detection limit , analytical chemistry (journal) , materials science , electrochemistry , chromatography , organic chemistry
A reactive electrode (reactrode) made of silver(i) hexacyanoferrate(III) (Ag‐ hcf ), graphite and paraffin has been developed for the determination of iron(III) ions in solutions down to a concentration of 0.12 mg L −1 . Silver ions are reduced to Ag 0 and the liberated hecacyanoferrate ions react with iron(III) ions from the solution to form Prussian blue. After this preconcentration step, the iron ions can be determined electrochemically by the characteristic signals of Prussian blue in differential pulse voltammetry. A nonlinear calibration plot is obtained which has a standard deviation of 13%. Pb 2+ , Cu 2+ and Ni 2+ interfere when they are at the same concentration as iron(III), whereas Cd 2+ does not interfere even at higher concentrations. The incorporation of an active reagent into the electrode material remarkably facilitates the analytical procedure and makes the use of a mercury electrode unnecessary.