title: Determination of Pb2+ ions by a modified carbon paste electrode based on multi-walled carbon nanotubes (MWCNTs) and nanosilica.
abstract: A novel carbon paste ion selective electrode for determination of trace amount of lead was prepared. Multi-walled carbon nanotubes (MWCNTs) and nanosilica were used for improvement of a lead carbon paste sensor response. MWCNTs have a good conductivity which helps the transduction of the signal in carbon paste electrode. The electrode composition of 20 wt% paraffin oil, 57% graphite powder, 15% ionophore (thiram), 5% MWCNTs, and 3% nanosilica showed the stable potential response to Pb(2+) ions with the Nernstian slope of 29.8 (+/-0.2)mV decade(-1) over a wide linear concentration range of 10(-7)-10(-2)mol L(-1). The electrode has fast response time, and long term stability (more than 2 months). The proposed electrode was used to determine the concentration of lead ions in waste water and black tea samples.
authors.affiliation: Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran, Iran. ganjali@khayam.ut.ac.ir
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Ganjali
authors.forename: Negar
authors.initials: N
authors.lastname: Motakef-Kazami
authors.forename: Farnoush
authors.initials: F
authors.lastname: Faridbod
authors.forename: Sepideh
authors.initials: S
authors.lastname: Khoee
authors.forename: Parviz
authors.initials: P
authors.lastname: Norouzi
mesh_terms: D002138:Calibration; D002244:Carbon / Q000032:analysis*; D004566:Electrodes; D006108:Graphite; D007854:Lead / Q000032:analysis*; D008567:Membranes, Artificial; D043942:Nanotubes / Q000032:analysis*; D012722:Sewage / Q000032:analysis; D012822:Silicon Dioxide / Q000032:analysis*; D013662:Tea / Q000737:chemistry; D013893:Thiram / Q000737:chemistry; D014865:Waste Disposal, Fluid
chemical_list: D008567:Membranes, Artificial; D012722:Sewage; D013662:Tea; D013893:Thiram; D007854:Lead; D002244:Carbon; D012822:Silicon Dioxide; D006108:Graphite