LEAD ION-SELECTIVE ELECTRODE BASED ON 4'-VINYLBENZO-L5-CROWN-5 HOMOPOLYMER

A PVC membrane electrode for lead ions based on 4'-vinylbenzo-15-crown -5 homopolymer as membrane carrier was prepared. The electrode exhibit s a Nernstian response for Pb2+ ions over a wide concentration range ( 4.0 x 10(-3) to 1.0 x 10(-6) M), with a limit of detection of 7.0 x 10 (-7) M. it has a response time of 80 s and can be used for at least 4 months without any considerable divergence in potentials. The proposed membrane electrode revealed very good selectivities for Pb2+ over a w ide variety of other cations and could be used in the pH range 2.0-6.0 . It was used as an indicator electrode in potentiometric titration of lead ions in both water and 90% methanol solutions. (C) 1998 Academic Press.