Determination of Pb2+ ions by a modified carbon paste electrode based on multi-walled carbon nanotubes (MWCNTs) and nanosilica.
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.
Ganjali
Mohammad Reza
MR
Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran, Iran. ganjali@khayam.ut.ac.ir
Motakef-Kazami
Negar
N
Faridbod
Farnoush
F
Khoee
Sepideh
S
Norouzi
Parviz
P
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
D008567:Membranes, Artificial; D012722:Sewage; D013662:Tea; D013893:Thiram; D007854:Lead; D002244:Carbon; D012822:Silicon Dioxide; D006108:Graphite