Using the Ethanolamine-Modified Nanoporous Silica as a PVC Membrane Electrode Modifier to Determination of Lead Ions

A PVC membrane electrode to determination of lead ions based on hydroxymethyl -modified SBA-15 nanoporous silica as a carrier was prepared. The electrode exhibits a Nernstian response for Pb2+ over a concentration range (1.0?10-1 to 1.0?10-4 mol L-1) with a slope of 28.9±0.2 mV per decade. The limit of detection of the sensor is 5.5?10-5 mol L-1. The sensor has a relatively fast response time (?10s) and a useful working pH range of 3.5– 8.0. Interference of some divalent cations was also evaluated. It was used as an indicator electrode in potentiometric titration of Pb2+ with EDTA and in direct determination of lead ion in wastewater and pepper samples. The results indicate that this electrode is sensitive for determination of Pb2+.