Quantitative Determination of Gadolinium Ion by a Gd3+-Liquid Membrane Sensor Based on 1-(4-Nitrophenyl)-3-(4-phenylazophenyl)triazene as a Sensing Material

In this work, a new gadolinium(III) PVC-membrane potentiometric sensor for the Gd3+ ion based on 1-(4-Nitrophenyl)-3-(4-phenylazophenyl)triazene (PPAT) has been prepared. The sensor shows a Nernstian slope of 19.9 +/- 0.2 mVdecade(-1) in a wide concentration range of 1.0x10(-6) to 1.0x10(-2) mol L-1 with a detection limit of 4.7x10(-7) mol L-1. It has a very short response time of about 10 s. The proposed electrode revealed high selectivity for Gd3+ ions over a number of cations including alkali, alkaline earth, transition and heavy metal ions and could be used in a pH range of 2.6-8.7. The fabricated Gd3+ electrode was successfully used as an indicator electrode in potentiometric determination of Gd(III) ions with standard solution of EDTA and the monitoring of Gd(III) ions in mixtures of different metal ions with quantitative results.