| dc.description.abstract |
A new PVC membrane sensor, which is
highly selective towards Ni (II) ions, has been developed
using a thiophene-derivative Schiff base as the
ionophore. The best performance was exhibited by the
membrane having the composition percentage ratio of
5:3:61:31 (ionophore:NaTPB:DBP:PVC) (w=w), where
NaTPB is the anion excluder, sodium tetraphenylborate
and DBP is the plasticizing agent (dibutyl phthalate).
The membrane exhibited a good Nernstian response for
nickel ions over the concentration range of 1.0 10 1–
5.0 10 6M (limit of detection is 1.8 10 6 M) with a
slope of 29.5 1.0mV per decade of activity. It has a
fast response time of<20 s and can be used for a period
of 4 months with good reproducibility. The sensor is
suitable for use in aqueous solutions of a wide pH range
of 3.2–7.9. The sensor shows high selectivity to nickel
ions over a large number of mono-, bi- and trivalent
cations. It has been successfully used as an indicator
electrode in the potentiometric titration of nickel ions
against EDTA and also for direct determination of
nickel content in real samples – wastewater samples
from electroplating industries and Indian chocolates. |
en_US |