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Amperometric Ion Sensing Using Polypyrrole Membranes
Author(s) -
Michalska Agata,
Walkiewicz Sebastian,
Maksymiuk Krzysztof
Publication year - 2003
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.200390061
Subject(s) - amperometry , polypyrrole , electrolyte , chemistry , potentiometric titration , supporting electrolyte , inorganic chemistry , membrane , electrochemistry , conductive polymer , redox , chloride , polymer , analytical chemistry (journal) , ion , electrode , chromatography , organic chemistry , biochemistry
Abstract Oxidation/reduction of conducting polymers, coupled with ion exchange between the polymer and electrolyte solution can be utilized for amperometric ion sensing. Electrochemically deposited “model” polypyrrole membranes doped by chloride (PPyCl) and hexacyanoferrate (PPyFeCN) anions were studied from the point of view of their advantages and limits for amperometric determination of electroinactive anions and cations, respectively. Monotonous dependences of the current on electrolyte concentration were obtained for short reading times after potential step application (in the range of ms). The experimental conditions were optimized to obtain linear dependences: log (current) vs. log (KCl concentration) within the range 10 −6 −1 M. The advantages of the amperometric method over the potentiometric one are highlighted: much lower effect of redox and pH interferences, wider concentration range, elimination of long conditioning procedure.