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Amide and Acyl‐Hydrazine Functionalized Calix[4]arenes as Carriers for Hydrogen Phosphate Selective Electrodes
Author(s) -
Yan Zhenning,
Li Xia,
Xu Yan,
Ye Baoxian
Publication year - 2007
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.200603810
Subject(s) - potentiometric titration , ionophore , chemistry , selectivity , membrane , amide , inorganic chemistry , ion selective electrode , titration , hydrazine (antidepressant) , electrode , organic chemistry , chromatography , catalysis , biochemistry
Anion‐selective solvent polymeric membrane based on hydrogen bond‐forming, neutral ionophores with amide or acyl‐hydrazine groups are described. The use of the two calix[4]arenes results in anion‐selective electrodes with a selectivity for phosphate. The electrodes of the optimum characteristic have the composition of 1 wt% ionophore, 66 wt% o ‐NPOE, 33 wt% poly (vinyl chloride) (PVC) and TDMACl (15 or 30 mol% relative to the ionophore 1 and 2 , respectively). The optimized membrane electrodes show Nernstian responses towards monohydrogen phosphate (−29.1 and −29.3 mV/decade) based on ionophore 1 and 2 , respectively, in a wide concentration range (1.0×10 −5 to 1.0×10 −2 or 1.0×10 −5 to 1.0×10 −1 M). The selectivity coefficients are determined with the fixed interference method and the activity ratio method. The electrodes display an anti‐Hofmeister series selectivity pattern and highly selective for HPO 4 2− over Cl − , Br − , CH 3 COO − , NO 3 − and SO 4 2− . The lifetime of the electrodes is at least 1 month and their response time is found to be 25 s. The proposed sensors could be put to analytical use both by direct potentiometry as well as potentiometric titration.