Polyvinyl chloride-based membranes of 3,7,11-tris (2-pyridylmethyl)-3,7,11,17-tetraazabicyclo [11.3.1] heptadeca-1(17),13,15-triene as a Pb(II)-selective sensor

A Pb2+-selective sensor was fabricated from polyvinyl chloride (PVC) matrix membranes containing the ionophore 3,7,11-tris (2-pyridylmethyl)-3,7,11,17-tetraazabicyclo [11.3.1] heptadeca-1(17),13,15-triene (I). The effects of anion excluders (KTpClPB, NaTPB) and plasticizers (o-NPOE, DBP, DOP) on the performance of the membrane sensor were studied. The membrane with the composition of I:PVC:o-NPOE:KTpClPB in the percentage ratio (wt.%) of 2:32:60:6 exhibited the best performance, having a slope of 28.5 +/- 0.2 mV/decade in the concentration range 10(-6)-10(-1) M, a response time of 20 s and a lifetime longer than four months. The sensor was selective for Pb2+ ions over other monovalent, divalent and trivalent interfering cations and could be used in the pH range of 5-8. The high selectivity in the presence of Cd2+ may be important for further studies. The efficiency of the proposed sensor was demonstrated by its application in Pb2+ ions determination in water samples. (C) 2010 Elsevier B.V. All rights reserved.