Novel terbium(III) sensor based on a new bis-pyrrolidene Schiff's base

Here a terbium-selective solvent polymeric membrane sensor based on N,N,-bis(pyrrolidene) benzene-1,2-diamine, poly(vinyl chloride) (PVC), benzylacetate (BA) plasticizer, and an anionic additive is described. At a pH range of 3.5-7.7, this sensor responds to dysprosium in a linear range from 1.0 × 10−5 to 1.0 × 10−1 M, with a slope of 19.8 mV per decade and a detection limit of 7.0 × 10−6 M. It has a fast response time of <20 s in the whole concentration range, and can be used for at least 2 months without any considerable divergences in the potentials. The proposed sensor revealed comparatively good selectivity with respect to common alkali, alkaline earth, transition and heavy metal ions. It was used as an indicator electrode in potentiometric titration of fluoride ions, and in determination of F− ion in some mouth washing solutions preparations.