ISSN 1070-4272, Russian Journal of Applied Chemistry, 2016, Vol. 89, No. 12, pp. 2001−2007. © Pleiades Publishing, Ltd., 2016.
The text was submitted by the authors in English.
Over the last two decades, plenty numbers of ionophores
with high susceptibility to detect and determination of
various metal ions in diverse environmental and biological
samples have been developed which ﬁ nd considerable
applications in potentiometric sensor method [1–4].
The potentiometric ion selective sensors supply very
selective, simple, correct, and monetary method for on
line monitoring of different ions concentration without
any pretreatment or destruction of sample.
Holmium as like as most of the rare earths has a
wide range of applications with just a little toxicity. This
eleventh element in the lanthanide series has atomic
number 67 with a malleable and polished, smooth, silvery
physical appearance. There are applications of this rare
element is in nuclear reactors, magnetic ﬂ ux concentrator,
pigment industry and so on [5, 6].
As our interest is concerned to developing ion
selective electrodes [7–60], a novel ion selective elec-
trode for holmium(III) based on N,N′-dipyridoxyl(1,4-
butanediamine) (PYBA) that is one class of Schiff-base
ligands, will be covered in present article. Structure
of N,N′-dipyridoxyl(1,4-butanediamine) is not planar
(Scheme 1). The Schiff-base ligand plays the role of a
dianionic tetradentate ligand in the structure of the Ho
complexes. The binding of holmium(III) ions with N
donor atoms of PYBA has been established by coordina-
tion chemistry of lanthanides. This is the ﬁ rst report on
use of N,N′-dipyridoxyl(1,4-butanediamine) as ionophore
for metal ions.
Reagents. The required chemicals such as N,N′-
dipyridoxyl(1,4-butanediamine), the analytical reagent
OH HO N
Construction of a New Ho
Sensor Based on N,N′-Dipyridoxyl(1,4-butanediamine)
, H. A. Zamani
*, F. Joz-Yarmohammadi
, S. A. Beyramabadi
and M. R. Abedi
Department of Applied Chemistry, Mashhad Branch, Islamic Azad University, Mashhad, Iran
Department of Applied Chemistry, Quchan Branch, Islamic Azad University, Quchan, Iran
Received June 11, 2016
Abstract—N,N′-dipyridoxyl(1, 4-butanediamine) (PYBA) (2 wt % ), nitrobenzene (66 wt %), sodium tetra phe-
nyl borate (2 wt ), and poly vinyl chloride (30 wt %) were applied to create a PVC membrane in Ho
electrode (Ho-SE). Over the concentration range of 1.0 × 10
to 1.0 × 10
M in holmium(III) solution a linear
response with lower detection of limit equal 4.0 × 10
M was exhibited by new holmium(III) sensor. Ho-SE
possessed a Nernstian slope of 20.1 ± 0.8 mV decade
in very short time spans (9 s). The potential response of
electrode remains without any changes over a pH range of 2.77–8.71. The selectivity coefﬁ cient data which was
considered by matched potential method for variety of common cations indicated no signiﬁ cant interference. An
acceptable recovery for Ho
in the blend of several cations has been achieved. The utility of Ho-SE in potentio-
metric titration as an end point indicator electrode gave successfully results.