Lanthanide Recognition: Monitoring of Praseodymium(III) by a Novel Praseodymium(III) Microsensor Based on N$'$-(Pyridin-2-Ylmethylene)Benzohydrazide

In this work, for the first time, we introduce a highly selective and sensitive praseodymium(III) microsensor. Npsila-(pyridin-2-ylmethylene)benzohydrazide (PBH) was used as a membrane-active component to prepare a highly sensitive Pr(III)-selective polymeric membrane microelectrode. The electrode exhibits a Nernstian response toward Pr(III) ions over a very wide concentration range (1.0 times 10
^-3
-1.0 times 10
^-8
M), with a detection limit of 7.0 times 10
^-9
M (~1 ng/ml). It has a very fast response time in the whole concentration range (~10 s). The proposed microelectrode can be used for at least six weeks without any considerable divergence in potentials. The proposed membrane sensor revealed very good selectivity toward Pr(III) ions over a wide variety of other metal ions including common alkali, alkaline earth and, specially, lanthanide ions. It could be used in the pH range of 3.0-8.5. The Pr(III) microelectrode was used as an indicator electrode for the titration of 20 ml of a 1.0 times 10
^-6
M Pr(III) ions with a 1.0 times 10
^-4
M EDTA.