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Blank response at glassy carbon electrodes in a flow injection system
Author(s) -
Xu Yan,
Halsall H. Brian,
Heineman William R.
Publication year - 1992
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.1140040108
Subject(s) - glassy carbon , transient (computer programming) , electrode , blank , transient response , analytical chemistry (journal) , materials science , ionic bonding , current (fluid) , ionic strength , carbon fibers , chemistry , cyclic voltammetry , electrochemistry , thermodynamics , chromatography , composite material , ion , organic chemistry , aqueous solution , composite number , physics , computer science , electrical engineering , engineering , operating system
The blank response at glassy carbon electrodes in a flow injection system consists of a transient component and a steady state (residual current) component. The transient response is attributed to nonfaradaic current and faradaic current from the oxidation‐reduction of electroactive surface functional groups on glassy carbon. The magnitude of the transient response was dependent on the potential applied to the electrode, temperature, ionic strength and pH of the injected sample solution, and independent of the flow rate. A linear relationship exists between the transient response and the difference in concentration of ionic species or pH between injected sample and the carrier. A differnce of 0.01 M ionic concentration or 0.04 pH unit between carrier and injected sample could change the transient charge by ca. 0.038 μC/cm 2 . The shape of the transient response due to pH difference at high positive potential indicates that some changes occur on glassy carbon surface in this potential region.