Premium
Evaluation of electrodes coated with metal hexacyanoferrate as amperometric sensors for nonelectroactive cations in flow systems
Author(s) -
Thomsen Karsten N.,
Baldwin Richard P.
Publication year - 1990
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.1140020402
Subject(s) - electrode , amperometry , chemistry , selectivity , inorganic chemistry , nitric acid , metal ions in aqueous solution , ammonium , flow injection analysis , ion selective electrode , ion , metal , chromatography , nickel , electrode potential , analytical chemistry (journal) , detection limit , electrochemistry , organic chemistry , catalysis
Two electrodes modified with either nickel or cupric hexacyanoferrate films were evaluated and compared as sensors for nonelectroactive cations in a flow‐injection system. Both gave responses for group 1A and ammonium ions, but only the electrode modified with cupric hexacyanoferrate was sufficiently stable for use in flowing solutions. This electrode responded to K + , NH 4 + , Rb + , and Cs + ions rather selectively. Within this group, the selectivity could be controlled from general to almost specific toward Cs + by the potential at which the electrode was poised. The electrode was compatible with a mobile phase of dilute nitric acid commonly used in ion chromatography, and chromatographic detection limits of 2 × 10 −7 M and linear responses over two decades were obtained. The electrode was applied to the ion chromatographic analysis of K + and NH 4 +in urine and K + in blood serum samples.