Novel Pr(III)-selective membrane sensor based on a new hydrazide derivative

A novel Pr(III)-selective membrane sensor based on N′-(pyridin-2-ylmethylene)benzohydrazide (PBA) was prepared. The plasticized membrane sensor on N′-(pyridin-2-ylmethylene)benzohydrazide exhibits a Nernstian response for Pr(III) ions over a relatively wide concentration range (1.0 × 10−2 to 1.0 × 10−6 M) with a limit of detection of 8.0 × 10−7 M (∼115 ppb). It has a fast response time of ∼20 s and can be used for at least 6 weeks without observing any major deviation. The sensor revealed very good selectivity with respect to common alkali, alkaline earth, and especially lanthanide metal ions (cerium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutertium). The response of the proposed sensor is independent on pH in the range 3.5–8. It was used as an indicator electrode in potentiometric titration of Pr(III) ions and indirect determination of Pr(III) in water samples.