A PVC‐Based Vanadyl Phosphate Membrane Potentiometric Sensor for Vanadyl Ions

ABSTRACT

Poly(vinyl chloride) (PVC)‐based membrane of vanadyl phosphate has been fabricated using 2‐nitrophenyl octyl ether (NPOE) and 2‐nitrophenyl pentyl ether (NPPE), as plasticizing solvent mediators. The best sensor having composition ionophore:PVC:NPOE (wt.%) 10:55:35 exhibits linearity in the concentration range 1.0 × 10⁻⁶–1.0 × 10⁻¹ M with a Nernstian slope of 29.5 mV per decade of concentration. The static response time of the sensor is <5.0 s and it can be used for a period of 14 days without any divergence in potentials. The sensor performs satisfactorily between pH 2.0 and 4.0. It exhibits good selectivity over a number of cations and was used as an indicator electrode in the potentiometric titration of vanadyl ions with EDTA.

Keywords:

• Vanadyl ion
• Ion‐selective electrode
• Potentiometry
• Sensor

ACKNOWLEDGMENT

We gratefully acknowledge the support of this work by Tarbiat Modarres University Research Council.