Quantitative monitoring of terbium ion by a Tb3+ selective electrode based on a new Schiff's base

Solution study showed N,N'-bis(5-nitrosalicylidene)-2-aminobenzylamin (L) trends toward Tb3+ ion. Then, it was used as a suitable ionophore in construction of terbium ion selective electrode. The electrode with composition of 30% PVC, 65% solvent mediator (NB), 3% ionophore (L) and 2% anionic additive (NaTPB) shows the best potentiometric response characteristics. It displays a Nernstian behavior (20.1 mV decade(-1)) over the concentration range 1.0 x 10(-6) to 1.0 x 10(-2) mol L-1. The detection limit of the electrode is 6.3 x 10(-7) mol L-1. It has a very short response time (similar to 10 s) and a useful working pH range of 2.6-9.4 for at least 2 months. The proposed membrane sensor shows excellent discriminating ability towards Tb3+ ions with regard to several alkali, alkaline earth, transition and heavy metal ions. To investigate the analytical applicability of the sensor, it was successfully applied to the determination of terbium in certified reference material. (C) 2010 Elsevier B.V. All rights reserved.