Determination of Vanadyl Ions by a New PVC Membrane Sensor Based on N, N'-bis-(Salicylidene)-2,2-Dimethylpropane-1,3-Diamine

N, N'-bis-(salicylidene)-2,2-dimethylpropane-1,3-diamine (NNPD) was found to be a suitable neutral ion carrier for the construction of a highly selective and sensitive vanadyl membrane sensor. Poly(vinyl chloride) (PVC) based membranes of NNPD with potassium tetrakis (p-chlorophenyl) borate (KTpCIPB) as an anionic excluder and diethyl sebacate (DES), dibutyl phthalate (DBP), banzyl acetate (BA) and o-nitrophenyloctyl ether (NPOE) as plasticizing solvent mediators were investigated in vanadyl membrane sensors. A membrane, composed of NNPD-PVC-KTpCIPB-DES with the ratio 4.0:30.0:1.0:65.0, works well over a wide concentration range (7.0 times 10
^-
6 to 1.0 times 10
^-
2 M) with a Nernstian slope of 28.8plusmn0.3 mV per decade of activity between pH values of 4.0 and 5.10. The detection limit of the sensor was calculated to be 5.0 times 10
^-
6 M. It displays satisfactorily good discrimination toward vanadyl ions with regard to most common transitional metal ions. The proposed sensor demonstrates a short response time (-10 s). It was successfully applied for the determination of vanadyl ions in water samples