Lead is a poisoness element which can cause damage to the nervous system and the kidneys. In this research, a PVC based lead selective electrode was prepared based on 2,9-dihydroxy-1,10- diphenoxy-4,7-dithia decane as ionophore, NPOE as plasticizer, PVC as neutral matrix. The effect of membrane composition on the electrode performance was evaluated. Under the optimized conditions (PVC:30.3%; NPOE:61.6%; ionophore:8.1%), the electrode gave a nernstian response over a wide concentration range (1× 10 -5 to 1× 10-1M) with a slope of 29.2±2.2 mV /dec at 25°C. The detection limit for this electrode is 1×10-5 M. The electrode showed a fast response time (10 s) and could be used for 40 days without any appreciable change in its sensitivity. It was applicable in the pH range of 2-9 and was successfully used as an indicator electrode for potentiometric titration of Pb+2 with EDTA. The effect of the interfering ions on the selectivity of electrode were also studied.

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