Lead-selective membrane potentiometric sensor based on a recently synthesized dimethyl benzo tetrathia fulvalene

A PVC membrane electrode for lead ion based on dimethyl benzo tetrathia ful valene(DMBTTF)as membrane carrier was developed. The electrode exhibits a N ernstian response for Pb(2-)over a wide concentration range (10(-2)-10(-5) M) with a limit of detection of 8 x 10(-6)M. It has a response time of 20s and can be used for at least 2 months without any considerable divergence i n potentials. The proposed membrane sensor revealed good selectivities for Pb2- over a wide variety of other metal ions and could be used in pH range of 3.0-6.0.It was used as an indicator electrode in potentiometric titratio n of lead ions in both water and 90% methanol solutions.