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Studies on the phase boundaries and the significance of ionic sites of liquid membrane ion‐selective electrodes
Author(s) -
Bühlmann Philippe,
Yajima Setsuko,
Tohda Koji,
Umezawa Kayoko,
Nishizawa Seiichi,
Umezawa Yoshio
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.1140070905
Subject(s) - ionophore , membrane , attenuated total reflection , chemistry , potentiometric titration , ionic bonding , ion selective electrode , ion , analytical chemistry (journal) , phase (matter) , crown ether , inorganic chemistry , infrared spectroscopy , chromatography , organic chemistry , selectivity , biochemistry , catalysis
Attenuated total reflectance infrared spectroscopy (ATR‐IR) has been used to study the cation permselectivity of liquid‐membrane ion‐selective electrodes (ISEs). All spectroscopic evidence was found to agree with the interpretation of permselectivity as being due to complete exclusion of counter‐ions from the boundary phase. Compared to ATR‐IR, optical second harmonic generation (SHG) has an even more pronounced surface sensitivity. It has been demonstrated to be a promising new technique for the study of ISE response mechanisms, as it allows one to observe the actual phase boundary. On the other hand, further potentiometric evidence for the influence of ionic sites on the emf response was found, both by a study of membranes free of ionic sites as well as by the investigation of leaching processes at poly(viny1 chloride) membranes. Finally, the use of a photoresponsive crown ether ionophore allowed the determination of emf response characteristics in relation to the ionophore concentration without any changes in the membrane composition.