Fabrication of a novel holmium(III) PVC membrane sensor based on 4-chloro-1,2-bis(2-pyridinecarboxamido)benzene as a neutral ionophore

Center of Excellence in Electrochemistry, University of Tehran, Tehran, Iran; Endocrine & Metabolism Research Center of Medical Sciences, University of Tehran, Tehran, Iran
Journal of Applied Electrochemistry (Impact Factor: 1.84). 01/2007; 37(7):853-859. DOI: 10.1007/s10800-007-9321-5

ABSTRACT This paper introduces the development of an original PVC membrane electrode, based on 4-chloro-1,2-bis(2-pyridinecarboxamido)benzene
(CBPB) as a suitable carrier for the Ho3+ ion. The electrode presents a Nernstian slope of 19.7±0.3mV per decade for the Ho3+ ions across a broad working concentration range from 1.0×10−6 to 1.0×10−2M. The lower detection limit was 8.5×10−7M in the pH range 2.7–9.8, while the response time was rapid (<15s). Therefore, this potentiometric sensor displayed good
selectivity for a number of cations such as alkali, alkaline earth, transition and heavy metal ions. The practical applicability
of the electrode was demonstrated by its use as an indicator electrode in the potentiometric titration of Ho3+ ions with EDTA and in the determination of F- in mouth wash samples.

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