Abstract:
Highly selective all solid state electrochemical
sensor based on a synthesized compound i.e. 2-(1-(2-((3-
(2-hydroxyphenyl)-1H-pyrozol-1-yl)methyl)benzyl)-1Hpyrazol-
3-yl)phenol (I) as an ionophore has been prepared
and investigated for the selective quantification of
chromium(III) ions. The effect of various plasticizers, viz.
dibutyl phosphonate (DBP), dibutyl(butyl) phosphonate
(DBBP), nitrophenyl octyl ether (NPOE), tris-(2-ethylhexyl)
phosphonate (TEP), tri-butyl phosphonate (TBP),
dioctyl phthalate (DOP), dioctyl sebacate (DOS), benzyl
acetate (BA) and acetophenone (AP) along with anion
excluders NaTPB (sodium tetraphenyl borate) and
KClTPB (potassium(tetrakis-4-chlorophenyl)borate was
also studied. The optimum composition of the best performing
membrane contained (I):KClTPB:NPOE:PVC in
the ratio 15 : 3 :40 :42 w/w. The sensor exhibited near
Nernstian slope of 20.1 0.2 mV/decade of activity in the
working concentration range of 1.2 10 7–1.0 10 1 M,
and in a pH range of 3.8–4.5. The sensor exhibited a fast
response time of 10 s and could be used for about
5 months without any considerable divergence in potentials.
The proposed sensor showed very good selectivity
over most of the common cations including Na+, Li+, K+
, Cu2+, Sr2+, Ni2+, Co2+, Ba2+, Hg2+, Pb2+, Zn2+, Cs+,
Mg2+, Cd2+, Al3+, Fe3+and La3+. The activity of Cr(III)
ions was successfully determined in the industrial waste
samples by using this sensor.
