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The application of various immobilized crown ether platinum‐modified electrodes as potentiometric and amperometric detectors for flow injection analyses of catechol and catecholamines
Author(s) -
Lunstord Suzanne K.,
Ma YiLong,
Galal Ahmed,
Striley Cynthia,
Zimmer Hans,
Mark Harry B.
Publication year - 1995
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.1140070504
Subject(s) - potentiometric titration , amperometry , flow injection analysis , chemistry , ascorbic acid , catechol , crown ether , potentiometric sensor , chromatography , ether , electroanalytical method , detection limit , electrode , inorganic chemistry , nuclear chemistry , electrochemistry , organic chemistry , ion , food science
Different crown ethers were electrochemically polymerized or adsorbed onto a platinum electrode for the analysis of catechols by either static potentiometric, potentiometric FIA or amperometric FIA. The static potentiometric responses of all the crown ether modified electrodes were linear over about three decades of catechol concentration (10 −5 −10 −8 M). The potentiometric FIA response of all the crown ether modified electrodes exhibited linear responses over four decades of catechol concentration (10 −2 −10 −6 M). The amperometric FIA responses were linear over a 10 −2 −10 −5 M range. Comparing the different techniques; static potentiometric, potentiometric FIA, and amperometric FIA, all had markedly different response slopes for the different crown ethers. Overall, the crown ether modified electrodes, except for an open‐crown ether, displayed excellent response stability for successive injections in both FIA modes. The lowest detection limits were about 0.5 × 10 −6 M for the potentiometric FIA with minimal interference from ascorbic acid, uric acid and acetaminophen. For amperometric FIA the detection limits were about 0.5 × 10 −5 M, but for ascorbic acid, uric acid, and acetaminophen the interference was significant. Experimental parameters which influence the mechanism of the potentiometric response are discussed.