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Application of a New pH‐Sensitive Electrode as a Detector in Flow Injection Potentiometry
Author(s) -
Kahlert Heike,
Pörksen Jens R.,
Isildak Ibrahim,
Andac Müberra,
Yolcu Murat,
Behnert Jürgen,
Scholz Fritz
Publication year - 2005
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.200403218
Subject(s) - electrode , hydrochloric acid , electrolyte , detector , analytical chemistry (journal) , reference electrode , saturated calomel electrode , buffer solution , chemistry , volumetric flow rate , flow injection analysis , potentiometric sensor , buffer (optical fiber) , materials science , chromatography , inorganic chemistry , potentiometric titration , detection limit , optics , electrical engineering , physics , engineering , quantum mechanics
A new pH sensitive detector for flow‐through potentiometry was developed on the basis of a graphite/quinhydrone composite electrode. The detector was constructed of two polymethylmethacrylate plates between which a 0.1 mm thick sensitive layer is situated. After drilling a hole through the plates, a ring of the sensitive layer is exposed to the solution stream. A conventional calomel reference electrode was placed downstream following the flow‐through sensor. The response behavior in different electrolyte solutions was investigated. The detector shows a Nernstian behavior for injections of hydrochloric acid into a KCl background solution as well as for the steady state response in concentration step experiments using hydrochloric acid and buffer solutions. The response time is sufficiently short for FIA applications ( T 95 between 3 and 5.4 s). The influences of flow rate and injection volume on the detector signal are discussed.