Neodymium(III)-PVC membrane sensor based on a new four dentate ionophore

A new selective Nd(III) sensor has been made by using N,N'-bis(quinoline-2-carboxamido)-4,5-dimethylbenzene (H2L4) as a suitable ionophore. The sensor exhibits Nernstian response to Nd(III) ions in the concentration range of 5.0 x 10-6 to 1.0 x 10-2 M. It displays a Nernstian slope of 19.5 ± 0.4 mV/decade in the pH range of 2.9-9.2. The proposed sensor also exhibits a fast response time of < l0 s. The detection limit of the proposed sensor is 4.8 x 10-6 M, and it can be used over a period of 10 weeks without significant changes in its response. Furthermore, the electrode showed high selectivity toward Nd(III) ion respect to all other lanthanide ions tested. The practical utility of the sensor was demonstrated by using it as an indicator electrode in the potentiometric determination of Nd(III) ions in certified reference material and spiked water samples.